Naturalized Approaches to Theory Ladenness: Evidence from

Cognitive Psychology, History, and the Ecological Validity

Argument

William F. BrewerUniversity of Illinois at Urbana-Champaign

Talk Presented at the Conference on the Theory-Ladenness of Experience, Heinrich-Heine University, Düsseldorf,

Germany, March 10-11, 2011

Overview of Talk

I. The Problem of Theory Ladenness

II. Ecological Validity ArgumentA. A Conceptual argument

III. Naturalized Phil of SciA. Framework from Cog Psy

B. Data from Cog Psy

C. Evidence from History of Sci

D. Conclusion

The Problem--Theory Ladenness

A. Norwood Hanson1. Tycho Brahe/Kepler thought experiment

2. “seeing is a ‘theory-laden’ undertaking” (1958, p. 19)

3. “we usually see through spectacles made of our past experience [and] our knowledge” (1969, p. 149).

B. Thomas Kuhn1. "Lavoisier...saw oxygen where Priestly had seen dephlogisticated air and where others had seen nothing at all” (Kuhn, 1962, p. 117).

2. "After a revolution scientists are responding to a different world" (Kuhn, 1962, p. 110).

C. Very strong psychological claims1. clear case in Phil of Sci of need for a naturalized approach

D Led some folk to relativism1. Thus the epistemological message of [this] work could be said to be..relativistic...It is relativistic because it suggests that belief systems cannot be objectively ranked in terms of their proximity to reality or their rationality." (Barnes, 1974, pp. 154)

E. Fodor counterattacks with modularity (1983, 1984)1. early perceptual processing occurs in modules that are not cognitively penetrable by the higher order cognition required by the theory laden claims

2. ‘objectivity’ of science saved!

F. Supported by:1. Raftopoulos (2001a, 2001b)

2. Gilman (1990, 1992)

The Ecological Validity Argument

A. Neisser (1978) “Memory: What are the important questions?”1. many laboratory memory tasks not relevant to phenomena of memory in real world

B. Brewer (2001) Ecological Validity in Psy Research1. there needs to be a clear link between the laboratory tasks studied by the scientist and the phenomena in the world the scientist is trying to understand

2. example: nonsense syllable learning literature in experimental psychology did not seem to be relevant to understanding memory for syntax, word meaning, schemata, etc.

C. Ecological Validity as Applied to Theory Ladenness1. the naturalistic data of interest to us are data relevant to the tasks the scientist carries out

2. we are interested in knowing if theory ladenness occurs for the the scientist’s perceptions of the objects the scientist is studying

3. we are interested in knowing if theory ladenness occurs for the scientist’s attention to the objects the scientist is studying

D. The Data Discussed by the Modularity Mafia do Not Have the Required Ecological Validity1. Fodor (1983, 1984) & Raftopoulos (2001a, 2001b) give us interesting data from studies of the very earliest stages of visual and neural processing

2. while the issues of the timing of the processing path for vision are of interest to vision scientists they are not the data we need in the Phil of Sci to address the theory ladenness issue

3. for the problems of interest to us we simply do not need to know if there is an early stage in vision (e.g., Marr’s 2 1/2 D) that is not cognitively penetrable.

4. for the issues of the Phil of Sci we need to know the outcome of the processing

5. to resolve the issues related to theory ladenness we need to know what the scientist perceived and what the scientist attended to in carrying out the process of science

E. Apply the Ecological Validity Criterion to the Lab Data from Cog Psy in this Talk1. I also have to play by these tough rules

2. You should compare the laboratory data I review to the episodes from the history of science and decide for yourself if the laboratory findings seem directed at the issues of interest (i.e. are ecologically valid)

F. So What do the Relevant Naturalized Data Tell Us?1. I claim the ecological argument undercuts the data that the modularity approach has attempted to use to eliminate the epistemological problems raised by theory ladenness

2. The core of this talk is a review of the appropriate evidence from current Cog Psy on the issue of theory ladenness.

A Framework for Understanding Theory Ladenness

A. Overemphasis of the Role of Visual Perception1. There is a long history in Western philosophy of focusing on visual perception in epistemology

2. British Empiricists a. Hume, Berkeley, Lock

3. Logical Positivists

4. Kuhn & Hanson postPositivists

5. Fodor’s modularity approach

B. Problems with this Overemphasis1. “It is data rather than perceptual beliefs that play a central evidential role in science and data are typically not descriptions of perceptual appearances or reports of perceptual belief at all" (Bogen & Woodward, 1992 p, 599).

2. in modern science with computer-based data acquisition and analysis the actual data used is rarely the direct perceptual observations of the individual scientist

C. Brewer & Lambert 20011. In Psychology of Science we want to study the scientific process from the initial designing of experiments to the final writing of a journal article

2. this approach reduces the role of visual perception but expands the potential role of top down influences to cover a much wider range

3. potentially relevant mental processes:a. perceptionb. attentionc. thinkingd. experimentinge. memoryf. communication of findings

D. Term “Theory will be Used Broadly1. in this talk will ignore the literature on different forms of mental representation (images, concepts, schemas, mental models, etc)

2. in this talk theory = any form of top-down knowledge

E. Laboratory Data Derived from Nonscientist Participants1. in an ideal world the data from Cog Psy would be based on studies of actual scientists

2. in practice almost all of the data will be from children and undergraduate participants (actual data from scientists will be discussed along with the historical cases)

3. while there are many differences between scientists and ordinary folk we hope that the underlying mental processes are the same

F. Top Down--Bottom Up Synthesis1. modern framework (e.g., Lindsay & Norman, 1977)

a. perception is conceived as the product of both bottom-up and top-down factors

b. bottom-up: physical information coming into the eye or other sensory organ

c. top-down: beliefs or theories about what the individual is perceiving

2. connectionist approaches (e.g., McClelland &Rumelhart, 1981) a. give a natural account of the interaction of the

two forms of information

3. neurosciencea. recent work suggests there are actually more

top-down descending neural pathways than ascending paths in the visual system

4. epistemological consequencesa. allows evidence for top-down theory-driven

effectsb. bottom-up information from the world

can help avoid the slippery slope to relativism

5. Fodor’s modularity viewa. rejects the top/down-bottom-up view which is the

modal view in current cognitive psychologyb. given Fodor’s visibility in philosophy I think it

might be easy for philosophers not to realize that his view is not the standard view

G. Strongest Top-down Effects Occur with Degraded Input

1. Brewer & Lambert, (1993, 2001); Brewer & Loschky, (2005) review of the Cog Psy literature suggests that the amount of information that comes from top-down processes various across perceptual tasks

a. hallucinations & dreams = ~100% top-down a. vivid, unexpected object being attended to would

involve much bottom up information

2. the examples where theory has a very strong effect on perception tend to be cases of degraded stimuli, stimuli being presented for a very short time, or ambiguous stimuli.

H. Facilitatory & Inhibitory Role of Theory on Understanding the World (the Two Edged Sword)

1. Brewer & Lambert, (1993, 2001) focused too strongly on the negative role of top-down processes

2. we wanted to show the effects of the top-down processes and so emphasized laboratory studies and historical cases that typically showed a negative impact on the performance of the participant in the lab or the scientist in the historical episode

3. in laboratory studies we typically know what the stimuli was so we can easily determine if the impact of theory was facilitatory or inhibitory

4. the data show that having a correct theory about the stimulus can reduce perceptual thresholds, direct attention, etc.

5. (old fashioned view about to come!) I want to argue in this talk that the historical episodes from the history of science can be treated the same way. In science we often know which view of the world was correct (no scare quotes!). So practicing Whig History in the history of science allows us to better understand the psychological processes that were occurring at the time (of course, the scientist working in real time never knows if the theory they are working with maps the world successfully)

6. so I claim that the scientist who is lucky enough to have a theory that reflects the nature of the world (most of us working scientists are un-reconstructed realists) will show the positive benefits of improved perception of the objects in the scientific domain, will be able to direct attention to the appropriate objects, will better be able to interpret information, etc.

7. and for the scientist who is unlucky enough to hold an incorrect view of the world there will be inhibition in all the same psychological processes in this scientist’s attempt to understand the world

8. this revived Whig History allows me to understand the psychological processes the were at work in many historical episodes

9. the Neptune/Vulcan example--(a) when Galle received the theoretical information

from Le Verrier about the likely location of Neptune it directed his attention to the correct region of the sky and allowed him to discover Neptune--a clear case of facilitation

(b) however, when similar theoretical calculation were done for Mercury they led to many false sightings of the hypothetical planet Vulcan (a planet we now know does not exist)--a clear case of inhibition

10. so this (almost counterbalanced design!) supports my argument that when a scientist has a theory that correctly maps the world the mental processes will facilitate the ability of the scientist to understand the world, while the reverse in true for scientists with a theory that does not map the world

I. Strategy in the Next Part of the Talk

1. take a naturalized approach to the philosophical discussions of the theory-ladenness of perception

2. study perception & the other processes

3. for each mental process--look for evidence from:a. cognitive psychologyb. history of science

Evidence on the Issue of Theory Ladennes from Cog Psy and History of Sci

I. Perception--Psychological Evidence

A. Overview

--> 1. perception

2. attention

3. thinking

4. experimenting

5. memory

6. communication

A. What do you see here?

B. What do you see here?

C. What do you see here?

D. What do you see here?

E. What do you see here?

F. What do you see here?

G. Ambiguous Figures--Perceptual Info (e.g., Leeper, 1935)

1. stimuli & procedurea. unambiguous version of an ambiguous figureb. note that this ambiguous figure gives rise to two

different perceptual experiences c. later show ambiguous versiond. ask what the participants see

2. resultsa. if 1st see unambiguous old woman then almost

all participants see the ambiguous figure also as old woman

b. if 1st see unambiguous young woman then almost all participants see the ambiguous figure as young woman

3. analogue in science:a. scientist looking at an idealized textbook drawing

& then showing facilitation when looking a real slides4. Bill Bechtel anecdote--anti interpretation

H. Ambiguous Figures--Rat/Man (Bugelski & Alampay, 1961)

I. Ambiguous Figures--Perc Class Info (e.g., Bugelski & Alampay, 1961)

1. stimuli & procedurea. show participants set of animal pictures (no rat)b. later show ambiguous rat/man picturec. ask what the participants see

2. resultsa. up to 80% of participants saw rat if had

previously seen the set of animal pictures (

J. Ambiguous Figures--Conceptual Info (e.g., Liu, 1976)

1. stimuli & procedurea. participants hear passage about ratsb. later show ambiguous rat/man picturec. ask what the participants see

2. resultsa. doubled the rate of seeing the ambiguous figure

as as rat

3. conclusiona. seems like a clear example of high-level

conceptual theory information influencing the perceptual experience

K. Vague Stimuli--Reynolds, 19851. stimuli: fragmented pictures

a. initially seem to be random shapes (bottom-up info)

then shift to being perceived as a meaningful obj

2. design: 3 conditionsa. no info [9%]b. group told figs were meaningful picts [55%]c. group given more specific top down conceptual

info (e.g. “animal”) [74%]

3. these stimuli give a Gestalt like experience (the random fragments are suddenly perceived as a meaningful object) so likely to be a true perceptual effect not a conceptual inference

L. Reynolds 1985

M. Vague Scientific Stimuli (Chinn & Malhotra, 2002)

1. it might be possible to use the ecological validity argument against the previous laboratory experiments

2. is there any theory laden evidence for an experimental situation even more like those in science?

3. children watching an actual scientific experiment

4. procedurea. experimenters show 4th grade children Galileo’s experiment of dropping heavy & light objectsb. children must report if they saw:

(1) heavy & light rocks hit at same time(2) heavy hit first or light hit first

c. this a very difficult perceptual judgment

5. children have different naive theories:a. some believe heavy objects fall fasterb. some believe both fall at same speed

4. resultsa. theory hit same 72% report both hit at same

timeb. heavy faster 25% report both hit at same time

5. this experiment does not provide ironclad evidence that the children’s theories influenced their perceptions, but they certainly show that the children’s theories influenced their observations and that is the crucial issues (for the ecological argument)

N. Conclusions: Perception--Psychological Evidence

1. the experiments appear to give strong support to the top-down bottom-up synthesis.

2. note--in all the strong cases of theory ladenness the stimuli are ambiguous, degraded, or required a difficult perceptual judgment (so top-down factors can override the bottom up factors)

3. but strong bottom-up information will override top-down beliefs

a. show Galileo a nice Voyager color photograph of Saturn and he would clearly see the rings

4. so no need to slide down the slippery slope to relativism

5. now shift to evidence from the history of science to see if it is consistent with the laboratory studies from psychology

6. the data from history cannot be, by its nature, as clear as the experiments where we can control and manipulate variables, but it also provides convincing evidence for the interplay of top-down and bottom-up processes in the perception of actual episodes in the history of science

II. Perception--History of Science

A. Overview

--> 1. perception

2. attention

3. thinking

4. experimenting

5. memory

6. communication

A. Rings of Saturn

1. astronomers were expecting to see moons circling Saturn since that is what they had seen with Jupiter

2. for 40 yrs they drew Saturn witha. moons orb. handles coming out of the poles

3. see drawings

4. Drawings of Saturn (Van Helden, 1974)

B. Astronomer’s Psychological Conclusions1. several astronomers have reviewed this and other examples of top-down factors in observational astronomy and have come to conclusions very similar to mine:

2. Sheehan (1988) stated “Once a definite expectation is established, it is inevitable that one will see something of what one expects; this reinforces and refines one’s expectations in a continuing process until finally one is seeing an exact and detailed--but ultimately fictitious--picture” (p. 85).

3. Sheehan also noted the role of theory in facilitating astronomical observation. He stated, “It is often wondered, after an object is once discovered, that it was not found long before. Faint objects are often reported as detectable in telescopes two or even three times smaller

than those used for their discovery. Following the discovery of Saturn’s inner ring (the crépe ring)...for instance, the new ring was seen by a number of observers with small instruments” (p. 63).

4. Hetherington (1983) drew similar conclusions from the history of astronomy and concluded that having a theory is a two-edged sword. He pointed out that “scientists are guided by theory in selecting those observations that may be important” (p. 729) and that “the warping of judgments by knowledge, the influence on observational reports of preconceived opinion, is inevitable” (p. 729).

C. N-rays

1. after discovery of X-rays physicists went looking for other new forms of radiation

2. 1903 famous French physicist, Blondlot, announced discovery of N-rays

3. N-rays (see slide)a. produced by Nernst lampb. blocked by wet cardboardc. refracted by aluminum prismd. detection--a hard perceptual task

(1) increase in spark gap or (2) by faint phosphorescent glow of paint in

dark

4. 300 papers on properties of n-rays were published by 100 different scientists [ouch!] [one said discovered first!]

5. N-ray Apparatus

6. Wood, sceptical American physicist, went to Blondlot’s lab--in dark removed aluminum prism--experimenters could still see the n-rays--so by manipulating the physical factors while leaving the psychological ones constant he showed the effect was essentially all due to top-down theory

7. Conclusion(a) scientists with strong theoretical beliefs who

have to make very difficult perceptual judgments show strong theory-laden perception

D. Conclusions: Perception--Historical Evidence1. the historical record also appear to give strong support to the top-down bottom-up synthesis.

2. when a scientist’s theories map the world the psychological processes facilitate understanding the world, but when the scientist’s theory does not map the world the psychological processes inhibit the scientist’s ability to understand the world

3. there are clear examples of theory ladenness, but as with the evidence from cognitive psychology experiments the top-down effects almost always occur when the stimuli are ambiguous, degraded, or required a difficult perceptual judgment

4. but strong bottom-up information will override the top-down beliefs:

a. Tycho Brahe seeing a new star (supernova)b. if the data in Blondlot’s experiment had been

observations of a 10 on a meter with a 1 to 10 scale it is likely that the N-ray affair would not have occurred)

5. so, once again, we are not driven to relativism (but instead to the need for controls against the possibility of top-down theory-laden processes influencing experiments)

III. Attention--Psychological Evidence

A. Overview

1. perception

--> 2. attention

3. thinking

4. experimenting

5. memory

6. communication

A. Laboratory Inattentional Blindness (Mack & Rock, 1998)1. stimuli--cross presented very rapidly (200ms) faster than a shift in eye fixation possible

2. participants asked which arm of cross was longer

3. on a critical trial a totally unexpected objects (e.g., a small black square) was presented within one of the quadrants of the cross

4. depending on details of the experimental procedures from 25% to 80% report not having seen the unexpected object

5. control procedure of not asking for cross judgments and asking participants to report anything they saw showed essentially 100% reports of the unexpected object

B. Top-down --> Attention (Shinoda, Hayhoe & Shrivastava, 2001)

1. procedure

a. participants asked to carry out virtual driving task while obeying the usual traffic laws

2. stimulia. stop signs in usual locations at intersectionsb. stop signs in middle of a block

3. resultsa. usual locations ~100% responded tob. unexpected locations less than 33% responded

to

4. conclusionsa. top -down beliefs about typical stop sign location

was directing attention so signs with identical bottom-up sensory information in atypical locations were less likely to be attended to and responded to

C. Gorilla Study (Simons & Chabris, 1999)1. goal--can one get inattentional blindness with very vivid stimul

2. stimuli--two teams of payers passing basketball back and forth.

3. top-down attention--participans attention participants asked to mentally count the number of ball passes made by one team

4. Gorilla Walks Across Scene (Simons & Chabris, 1999)

5. resultsa. only about 50% of the participants report seeing

the gorilla

6. conclusionsa. can get inattentional blindness for very vivid

stimulib. theory-directed focusing of attention facilitates

theory-directed observation at the expense of non-theory dirrected observations

IV. Attention--Historical Evidence

A. Overview

1. perception

--> 2. attention

3. thinking

4. experimenting

5. memory

6. communication

A. “Pre-discovery” Observations

1. after some object is “officially” discovered astronomers look back at earlier data from locations that they now know the object should have been visible (to extend the database to calculate better orbits)

2. Forbes (1982) found 22 pre-discovery observations of Uranus.

3. so with no theory-based attention the earlier observations were not attended to and reported, but with theory-based attention Forbes found the 22 pre-discovery observations of Uranus

B. Brahe’s Bottom-Up Discovery of the 1572 Supernova1. In addition to the evidence for top-down processes operating in attention, the history of science also provides good examples where salient bottom-up information attracted attention in spite of strong top-down beliefs.

2. Tycho Brahe’s account of his discovery of the Supernova of 1572 makes the point well: “I was contemplating the stars in a clear sky, I noticed that a new and unusual star, surpassing the other stars in brilliancy, was shining almost directly above my head; and since I had, almost from boyhood, known all the stars of the heavens perfectly... it was quite evident to me that there had never been any star in that place in the sky, even the smallest, to say nothing of a star so conspicuously bright as this. I was so astonished at this sight that I was not ashamed to doubt the trustworthiness of my own eyes” (Brahe, 1929).

C. James Christy’s Discovery of Charon1. Christy was refining the orbit of Pluto by measuring it’s location against background stars

2. every few months he was sent a new photo of Pluto and he carefully measured its center against the background stars [see picture]

3. Discovery Picture of Pluto’s Moon, Charon

4. one day in 1978 he noticed a fuzzy bump on the picture he was measuring--he took out the last one he measured and saw a fuzzy bump in a different location--he the then examined all of the old pictures of Pluto in the Observatory and found the fuzzy bump on most

5. he calculated the changes in location of fuzz as if Pluto was rotating & found a precise orbital rotation period

D. Conclusions: Attention

1. both the laboratory studies from psychology and the historical accounts show that top-down processes can direct attention

2. but strong unexpected bottom-up information can attract attention

a. Brahe’s discovery of the 1572 supernovab. Rontgen’s observation of a glow in a darkened

room

3. so once again we have both top-down & bottom-up factors at work

4. no need for relativism

V. Thinking--Psychological Evidence

A. Overview

1. perception

2. attention

--> 3. thinking

4. experimenting

5. memory

6. communication

A. Theory Laden Interpretation of Text (Bransford &Johnson, 1972)

1. stimuli--obtuse passage [see next slide]

2. Bransford & Johnson, 1972 Obtuse Passage

The procedure is actually quite simple. First you arrange things into different groups depending on their makeup. Of course, one pile may be sufficient depending on how much there is to do. If you have to go somewhere else due to lack of facilities that is the next step, otherwise you are pretty well set. It is important not to overdo any particular endeavor. That is, it is better to do too few things at once than too many. In the short run this may not seem important, but complications from doing too many can easily arise. A mistake can be expensive as well. The manipulation of the appropriate mechanisms should be self-explanatory, and we need not dwell on it here. At first the whole procedure will seem complicated. Soon, however, it will become just another facet of life. It is difficult to foresee any end to the necessity for this task in the immediate future, but then one never can tell.

3. procedurea. participants hear passageb. three conditions: (washing clothes)

(1) no topic(2) topic after hearing passage(3) topic before hearing passage

4. results (recall--number of ideas right)a. no topic 2.8b. topic after 2.7c. topic before 5.8

5. schema/theory allows interpretation/comprehension which then facilitates memory

B. Top-down Interpretation of Scientific Data (nonscientists)(Brewer & Chinn, 1994)

1. participants:a. undergrads

2. designa. one group reads passages supporting Theory A

(dinosaurs were warm blooded)b. second group reads passages supporting Theory

B(dinosaurs were cold blooded)

c. so now have groups that believe different theories

about the dinosaurs

`

3. each group asked to evaluate data that was:a. consistent with the theory they read and

inconsistent with with other theory orb. inconsistent with the theory they read and

consistent with the other theorye.g., (consistent with cold) cold blooded animals

have small pineal systems & impressions in dinosaur skulls show small pineal systems

4. results (1 to 10 scale on belief in quality of the data)a. theory consistent data 8.0b. theory inconsistent data 6.0

5. conclusionsa. the exact same data is interpreted/evaluated

differently (in a theory consistent fashion)

VI. Thinking--Historical Evidence

A. Overview

1. perception

2. attention

--> 3. thinking

4. experimenting

5. memory

6. communication

A. Many Classic Paradigm Shifts in the History of Science Show Theory-Based Reinterpretation

1. flat earth vs. round earth

2. geocentric vs. heliocentric views(Ptolemy vs. Copernicus)

3. phlogiston vs. oxygen in chemistry

4. particle vs. wave theories of light

5. Newton vs. Einstein in physics

6. fixed continents vs. continental drift

7. intelligent design vs. natural selection

B. Example: Data on Shape of Africa & South America

C. Public Models (Interpretations) of the Iguanodon

1. paleontologists are sometimes in the embarrassing situation of having their theory-based interpretations on public display

2. the public models of the Iguanodon are wonderful examples

3. at first there are usually few bones so interpretation plays a larger role--then as more bones become available they provide bottom up evidence that constrains the interpretation

4. the first Iguanodon drawing appears to based on the characteristics of living Iguanas

5. Public Models (Interpretations) of the Iguanodon

6. the next model (made for the Crystal Place exhibition in 1851) appears to have been based on the characteristics of a Rhinoceros

7. the next models (Royal Museum of Natural History in Brussels) appears to have been influenced by Kangaroos

8. the current models are based on characteristics of raptors--fast moving predators with a rigid horizontal tail

9. the modern model builders note that in order to allow the Kangaroo like model to sit the model builders had to disarticulate the vertebrae (thus a beautiful example of top- down beliefs overriding bottom-up bone information)

10. conclusiona. theory --> interpretation --> construction of

models in paleontology

D. Thinking Conclusions

1. both the laboratory studies from psychology and the historical accounts show that top-down processes have a powerful effect on scientific thinking

2. interpretation (not perception) probably provides the strongest evidence for those who want to argue for relativism since the exact same data can be given radically different interpretations

3. but we also have the impact of bottom-up information

4. so once again we have both top-down & bottom-up factors at work

5. no need for relativism

VII. Experimenting--Psychological Evidence

A. Overview

1. perception

2. attention

3. thinking

--> 4. experimenting

5. memory

6. communication

A. Theory Driven Experimentation--Psychol Experiments(Klahr & Dunbar, 1988)

1. ask participants to learn how to program a programmable toy vehicle (Big Trak)

2. the experimenters observe the participants experiments (they punch program keys & see what the truck does)

3. resultsa. some participants just push key & see what

happens (inductive experimenters?)b. some participants developed theories and then

tried them out (theory testing experimenters)c. theory > induction in this particular task

4. conclusionsa. many participants are carrying out theory-

directed data gathering

VIII. Experimenting--Historical Evidence

A. Overview

1. perception

2. attention

3. thinking

--> 4. experimenting

5. memory

6. communication

A. Physical Constants

1. it turns out those precise looking numbers you see in physics books are actually arrived at by a committee!

2. every few years the committee meets and reviews the data from the current experiments and establishes the “official” value for a given constant

3. the committee publishes the changes in the official numbers for each constant over time

4. the data show that often the value for the constant remains within the error bar of the earlier value from one year to the next, but sometimes the values continue tocreep higher or lower until they are quite different [see left graph in the slide]

5. other times there will be a new, very different value many standard deviations from the first value and then the new values will track this new value [see right figure]

6. the physicists call this “intellectual phase locking”

7. These data reporting the measurements of physical constants over time capture the data from hundreds of experiments, so they establish the generality of intellectual phase locking; however they do not give an account of how the effect occurs.

8. Luckily a number of physicists have provided accounts of how they think the scientists’ beliefs in the data from the earlier experiments influence the way the later experiments were carried out.

9. Birge (1957) wrote that E. O. Lawrence stated that “In any highly precise experimental arrangement there are initially many instrumental difficulties that lead to numerical results far from the accepted value of the quantity being measured. It is, in fact, just such wide divergences that are the best indication of instrumental errors of one kind or another. Accordingly, the investigator searches for the source or sources of such errors, and continues to search until he gets a result close to the accepted value. Then he stops” (p. 51).

10 Allan Franklin quoted an ironic comment made within the physics community about a scientist “who fights the systematics until he or she gets the ‘right’ answer (read ‘agrees with previous experiment’) and then publishes” (1984, p. 791).

11. Richard Feynman, in his unique style, described the intellectual phase lock effect as revealed in measurement of the charge of the electron. “Millikan measured the charge on an electron by an experiment with falling oil drops, and got an answer which we now know not to be quite right. It’s a little bit off, because he had the incorrect value for the viscosity of air. It’s interesting to look at the history of measurements of the charge of the electron, after Millikan. If you plot them as a function of time, you find that one is a little bit bigger than Millikan’s, and the next one’s a little bit bigger than that, and the next one’s a little bit bigger than that, until finally they settle down to a number which is higher. Why didn’t they discover that the new number was higher right away? It’s a thing that scientists are ashamed of--this history--because it’s apparent that people did things like this: When they got a

number that was too high above Millikan’s, they thought something must be wrong--they would look for and find a reason why something might be wrong. When they got a number closer to Millikan’s value they didn’t look so hard. And so they eliminated the numbers that were too far off, and did other things like that� (1985, p. 342).

12. conclusiona. powerful evidence for theory driven

experimentation

IX. Memory--Psychological Evidence

A. Overview

1. perception

2. attention

3. thinking

4. experimenting

--> 5. memory

6. communication

A. Theory-Based Distortions in Memory(Zangwill, 1937)

1. stimulia. 5 ink-blots (animal like) & 1 ambiguousb. 5 ink-blots (mountain like) & same 1

ambiguous

2. procedurea. see one ink-blot & asked to draw it from memory

& tell what it reminded them of

3. the repeated ink-blot was recalled (drawn) in animal-like form when it had appeared with animal-like blots; while the exact same blot was recalled in mountain-like form when it had appeared with mountain-like blots.

4. conclusiona. theory-based distortions in memory

5. Stimuli & Data from Zangwill, 1937

X. Memory--Historical Evidence

A. Overview

1. perception

2. attention

3. thinking

4. experimenting

--> 5. memory

6. communication

A. Scientists Distort the Sci Literature in Memory(Vicente & Brewer, 1993)

1. Analysis of the scientific literature shows many distortions

a. Whorf-Sapir Hyp--number of words for snowb. Galileo dropped objects from the Tower of Pisac. deGroot’s study of expert chess players superior

memory for chess games

2. Vincente & Brewer, 1993 argue many of these may be memory distortions

3. gave undergrads non-distorted information about deGroot’s experiments and show they make memory errors just like those found in the scientific literature supporting the view that the many of the scientists’ distortions may have been theory-based memory errors

4. this suggests that when scientists are debating the merits of some scientific theory they may each be relying on a somewhat differently recalled set of evidence

(5. note that the practice of requiring the keeping of timely lab notebooks was likely introduced to reduce the possibility of memory errors)

B. Conclusions: Theory-Based Processes in Memory

1. both the laboratory studies from psychology and the historical accounts suggest that there may be theory-directed memory distortions of the scientific literature by scientists

XI. Communication--Psychological Evidence

A. Overview

1. perception

2. attention

3. thinking

4. experimenting

5. memory

--> 6. communication

A. Summarization of Text(van Dijk & Kintsch, 1978)

1. participants delete nonthematically related information2. so theory-laden communication of information

XII. Communication--Historical Evidence

A. Overview

1. perception

2. attention

3. thinking

4. experimenting

5. memory

--> 6. communication

A. Biased Reviews of the Scientific Literature

1. Chalmers, Frank, and Reitman (1990)

2. theory-based evaluation of the literature of review articles on radiotherapy after radical mastectomy

3. radiotherapists & surgeons: 72% classified as “enthusiastic”

4. other medical specialists: only 15% “enthusiastic”

XIII. Multiple Sources of Theory-Ladenness

C. Darwin on Theory Ladenness (Autobiography, p. 70)[mixture of perception, attention, & possibly interpretation]

1. [in 1831] “We spent many hours in Cwm Idwal, examining all the rocks with extreme care, as Sedgwick was anxious to find fossils in them;”

2. “But neither of us saw a trace of the wonderful glacial phenomena all around us; we did not notice the plainly scored rocks, the perched boulders, the lateral and terminal moraines.”

3. “Yet these phenomena are so conspicuous [when Darwin visited in 1842 after learning about Ice Ages] ...a house burnt down by fire did not tell its story more plainly than did this valley.”

XIV. Overall Conclusion

A. There is Psychological Data and Historical Data to Support the View that Theory-Ladenness Occurs in:

1. perception

2. attention

3. thinking

4. experimenting

5. memory

6. communication