How to conduct research experiments

Difficulties Encountered• MANY variables

– Psychology deals with behavior of living things.– Subjects behavior may change if subjects know they are

being studied– Researchers behavior may change based on what they

EXPECT or WANT to see

–Subjects behavior may change based on how the RESEARCHER acts (consciously or unconsciously)

–Even eliminating all variables creates a variable

Why did I pick this picture?

Types of Variables

• Independent – the variable that the researcher will change as part of the study

• Dependent – variables that occur as a result of changes in the independent variable

Example

• “Students score higher on SATs in the morning than in the afternoon.”– The independent variable is the time of day the

SAT is taken– The dependent variable is the score they get as

a result of the independent variable

Creating a Good Hypothesis

• A hypothesis must be specific and definable

• How about this?– “Religious people tend to be more helpful than

non-religious people.”– In your book - define “religious”

Try your own• Get into groups of three. As a team, brainstorm to

create hypothesis that incorporates an independent variable and a dependent variable.

• Come up with as many as you can in ten minutes.

• It should be something we can test in school

• After brainstorming, you will chose one that you will actually use in a later experiment

Example Hypothesis

• “Student who take part in extra curricular activities get better grades”

Experimentation• To test hypothesis, we generally use two groups –

a control group and an experimental group– Control group is unaffected by the independent variable– Experimental group is subjected to the independent

variable

Problems we may encounter• Remember: Subject behavior may change

BECAUSE they are being studied– May try to please the researcher (consciously or

unconsciously)– May change because they THINK they should be

changing – Subjects behavior may change based on how the

RESEARCHER acts (consciously or unconsciously)– Stereotypes – researcher may have a predetermined

outcome in mind that may skew the experiment

Placebo Effects• Placebo is a fake drug used

to test effects of real drugs• How its used

• Give one group the REAL medication

• Give the other group a sugar pill that they THINK is the real medication.

• People taking the placebo may get better because they THINK they are getting the real medication

•Compare groups–Are they getting better because of the drug, or because their mind is making them better on its own, because it EXPECTS the drug to work?

How to fix the problem

• Double Blind Experiment• Neither the subject nor the researcher

knows which is the control group and which one is the experimental group– (Neither knows who is getting the placebo)

Your Turn

• Explain how you could test your earlier hypothesis.– How will you eliminate other variables so your

subject is only affected by the independent variable you picked?

Methods of Research (p40)

Methods of Research

• Lab experiment – Objective, but not very “real world”– Good when using animals– Good if you need a very controlled

environment

Field Experiment

• Conducted in the “Real world”– may have many (unexpected, uncontrollable)

variables• Ex. The effects of heavy traffic on heart rate

– Put someone in a car, hook them up to monitors, put them in traffic, record the responses.

Survey• Can gather large amounts of data, but may not be

accurate due to questions or answers given

• Please Answer the Following Survey– “WHS should adopt which of the following policies for next

year– A. No Dress Code– B. A dress code that is rigidly enforced– C. A uniform designed by the students– D. A uniform consisting of Jacket and Tie for boys and

dresses for girls.

Naturalistic Observation

• Observe in natural environment, with the researcher isolated from subjects

• Can you name the good points and the troublesome points to this method?

Methods of Research continued• Interview- Can get personal feelings but may not

be honest– Subject may not be honest– Interviewer may be biased– Questions may be biased

• Subconscious cues may bias the interview

Case study

• Use records and previous data to study • Past may point to future but may not be

applicable or open to interpretation• Good for background info, but data gained

may not be applicable in all situations

Psychological test

• Objective and accurate if well written but limited in what they can test– IQ test is an example

• Helps eliminate bias found in other types of experiments

• Work well IF used to test very specific areas.

Longitudinal method

• In depth knowledge over long time, but EXTREMELY time consuming– Study kids 3 yrs old, then at 10 yrs old, then in

HS, then in college, then at 35. Note development

Cross Sectional Method

• Quick, but may have more variables than expected

• Get a representative sample from across many types of people– Old, young, women, men, different ethnic

groups, different social backgrounds, • See problems on p44.

Your Turn

• Conduct research on your hypothesis that uses three of the methods above.

• If doing a survey – write out the questions you will use

• If doing an interview – write out the questions

Ethics in Experimentation• AMA has established guidelines for experiments

– Subjects may always decline to participate at any time.• Openness and honesty

– If this will throw off the results, the experimenter at least must clear things up as soon as possible.

• Confidentiality– ID of subjects kept secret

• Experimenter must assess the risks carefully and explain the risks to the subject

Example of Ethics Issue

http://video.google.com/videoplay?docid=-22650799994423481&ei=humSSf_0C4LorgKMyNnHCw&q=stanford+prison+experiment&hl=en