Investigating Behaviour

Unit 2

Unit 2O Understand experimental and non

experimental methods.Tested by:O Nab (20 marks)O Research Investigation (completed as

course work and sent to SQA before Easter hols.

O Series of questions on a given scenario worth 20 marks in final exam.

Experimental BasicsOExperimentOVariables

O Independent variables (IV)ODependent variables (DV)

OHypothesisOOne tailedOTwo tailedONull

TasksO Listen to the following 2 experiments

and for each write down:O What was the IV?O What was the DV?O A one tailed, two tailed and null

hypothesis

O Memory Experiment

Group 1 wordsO BallO DogO BagO FallO MilkO TelephoneO WheelO PictureO CatO Winter

O BicycleO RabbitO ComputerO ComedyO FrontO SkyO BasketO NailsO SummerO Television

Group 2 WordsO PaperO FlatO ChocolateO TableO SwingO TigerO HallO ClimbO DuckO Seesaw

O NotepadO JewelleryO FilesO LionO PenO BurgerO FlowersO Ice CreamO InternetO Glasses

For this experiment:O What is the IV?O What is the DV?O What would the one-tailed

hypothesis be?O What would the two-tailed

hypothesis be?O What would the null hypothesis be?

O Which hypothesis was supported?

Task 3O For each of the following questions answer:a) Identify the IV and DVb) How could you operationalise the IV?c) How could you operationalise the DV?d) Write a fully operationalised one-tailed hypothesis.e) Write a fully operationalised two-tailed hypothesis

1. Do older people sleep more or less than younger people?

2. Do people rate food as more attractive looking when they are hungry?

Experimental DesignO Repeated Measures – when

participants complete all conditions (as our memory experiment)

O Independent Groups – when participants only complete one condition.

O Matched Pairs - uses independent groups but each participant in group A is paired with a participant in group B based on a pre-determined participant variable eg age, IQ, gender, etc

EvaluationO Repeated Measures (the one we used)

O One test may have been more difficult than the other. – Random allocation would counter this.

O By second test participants may have guessed purpose which will affect behaviour – Single Blind Design would counter this.

O Order effect. By second test the participants are either more practised or are bored which would confound the results (confounding variables) - counterbalancing

O Independent GroupsO No control for participant variables – group A might just be

more able. – Randomly allocate participants/matched pairsO Need more participants

O Matched PairsO Time consuming.O Can’t control all variables.

DesignO For each of the following write down whether they are

repeated measures or independent groups:1. Boys and girls compared on their IQ test.2. Hamsters are tested to see if one genetic strain is better

at finding food in a maze compared with another group.3. Reaction time is tested before and after a reaction time

training activity to see if test scores improve.4. Participants memory tested in the morning and

afternoon.5. 3 groups of participants tested to see if nouns, verbs or

adjectives are easier to remember.6. Participants are asked to rate photos as attractive or

unattractive.

TaskO A psychologist conducted a study to test

whether visual imagery helps memory. There were 2 lists to be recalled – one with words and one with pictures.

1. Describe how this experiment could be conducted for each of the 3 designs.

2. Which would be best? Explain your answer.3. For which would counterbalancing be

necessary?4. How would you design the counterbalancing?

Extraneous VariablesO Experimenter Variables (Eagly & Carli,

1983; Rosenthal, 1966; Rosenthal and Fode, 1963)

O Personal variables.O Demand CharacteristicsO The Hawthorne EffectO AgeO IntelligenceO Experience etc

O Situational VariablesO Order effectsO Time of day, temperature, noise, Mr

Haldane entering the room.

How to control these variables

O Pilot StudyO Standardised Procedures.

O Ensures all participants are tested under the same conditions to counter any situational variables.

O Standardised Instructions.O Like a script – counters investigator effects.

O Double Blind Design.O Neither the participant or the person

conducting the experiment knows the aims of the study

Experiment and Control Group

O In order to assert that an IV has affected the DV the experiment needs to be carried out in comparison with the results of the experiment without the DV.

O For example: The Drunken GoldfishO Control group – no alcoholO Experimental group – alcohol.

O NB if carried out with repeated measures design it is called control conditions and experimental conditions

Different types of experimentsO Laboratory

O Know they are taking part in the study.O Low in mundane realism.O Extraneous variables easier to control.

O FieldO High in mundane realism.O Don’t always know they are part of an experiment.

(ethics?)O Difficult to control extraneous variables.

O NaturalO Not always appropriate to change IVO Participants may be biased.O Causal conclusions can not be drawn as the IV has

not been deliberately manipulated.

TaskO The class will be divided in to 5 groups.

Each group needs to find the mean, median and mode of their topic.

1. No. of coloured paper clips.2. No. of coloured pins.3. No. of SG passes at Credit level.4. No. of hours slept last night.5. No. of siblings (including step and half

siblings).O You must design this task yourself and

decide what is the best way to collect the data etc.