Understanding

the Research Process

How do psychologists prove their theories?

• You decide that you are going to prove that:

being an organized student has NO or a BIG impact on

students’ grades.

• How would you go about proving this theory?

• Brainstorm with two or three other students.

Researchers Need

1. A plan

2. People willing to participate in the study

3. A method for collecting and analyzing the data

• Aim

• Target population

• Procedure

• Findings

• AIM – the purpose of the study. It indicates

which behavior or mental process will be

studied

• TARGET POPULATION – these are the group

who is being investigated

• PROCEDURE – the step-by-step process used by the

researcher to carry out the study.

Procedure must be carefully written so that it is

replicable.

• FINDINGS – states how the researcher interpreted the

data that were collected.

Must be interpret in terms of the culture in which it was

conducted.

A Classic Study: The Pygmalion effect

Rosenthal and Jacobson, 1968

• State the aim, procedure and findings of this study

undertaken by Rosenthal and Jacobson

• What is self-fulfilling prophecy?

(give an exemple of it from your experience)

Participants

who should be in the study?

• Participants – people who take part in a psychological

study

• Target population – specific group group, which

psychologists are interested in

• Representative sampling – is a sample which

represent whole population

Pick your participants

• You want to replicate the Pygmalion effect experiment. How

would you go about picking your participants?

Kinds of Sampling

• OPPORTUNITY SAMPLING –

whoever be there and agrees to

participate. Easy to get them,

but often lead to biased results

– Sampling bias – 2/3 of

research done at universities

uses exclusively students to

participate!

– Can you see a problem?

Kinds of Sampling

• SELF-SELECTED SAMPLE –

volunteers. Easy to obtain and

usually highly motivated, but don’t

always reflect whole population. – the example: http://www.youtube.com/watch?v=Br9goVGNPzc

• SNOWBALL SAMPLING –

Participants recruit other

participants from among their

friends and acquaintances.

Self- selected sample

• RANDOM SAMPLING – sampling where every member

of the target population has an equal chance of being

selected.

– Draw names out of a hat

• STRATIFIED SAMPLE - draws random samples from each

subpopulation in the group

– If school has 20% Roma students, then the sample must

include 20% of this sub population – so the sample is the

most accurate reflection of the actual distribution of the

school population.

Your Turn: Be a researcherYou want to make a study of people’s motivation to engage in exercise.

You decide to go to the local fitness center and conduct some

interviews. Discuss the following:

– If you use an opportunity sample at a local fitness center, which

group of people would be OVERREPRESENTED?

– Which group would be UNDERREPRESENTED?

– Would you get a more representative sample if

you advertised for participants in your school?

Ethics in Research

1. Informed Consent

2. Deception

3. Debriefing

4. Withdrawal from a study

5. Confidentiality

6. Protection from physical or mental harm

Check it out

• Review the research carried out by Rosenthal and

Jacobson - the Pygmalion effect.

• Was this study ethical?

• Discuss your reasons.

Evaluating Findings• INTERPRETING FINDING IS AN ESSENTIAL SKILL FOR A PSYCHOLOGIST.

• One way that a study can be evaluated is to assess whether it has any

practical applications.

• APPLICATION – how the theory or empirical study is used

– Studies of neurotransmitters are used to develop drugs to treat

depression, schizophrenia

– Research on effect of light on mood

– Use of memory research improves how we take evidence from

eyewitness testimony

VALIDITY AND RELIABILITY

Validity and Reliability

• VALIDITY

What doest it measure?

Temperature or perspiration level

• RELIABILITY

Does it show 36,6 degree when you

are healthy?

Does it produce the same readings in

the same circumstances?

Validity - the research is measuring

what it is supposed to measure

• Ecological Validity

– the study represents what happens in real life

– If took place in a laboratory may lack e.v.

– If it was so well controlled (in lab) that normal influences were eliminated, may lack

e.v.

– If stydy lacks of e.v. it may not predict what will happen outside of lab

• Cross-cultural Validity

– Is study relevant to other cultures? If not, it may be ethnocentric and based on values

and beliefs of one culture

Reliability – questionaries produce

the same results when re-tested

on the same people at different times

• results can be replicated

• if another research uses the exact same

procedure, it should give the same results

Points to Consider with Empirical Studies

1. Is the study based on a representative group of people (sample)?

– Is there a bias in the sample? Is one group overrepresented?

2. Was the study conducted in a lab or in a natural setting?

– Lab setting is artificial. It isn’t possible to be certain that

participants act as they would in real life

3. Were the participants asked to do things that are far from real

life?

– Remembering nonsense syllables? Lacks ecological validity

Points to Consider with Empirical Studies

4. Are the findings of the study supported/questioned by the

findings of other studies?

– Consider in what ways the findings are different and try to

explain how and why. Maybe you can suggest which study was

better designed and show which results seem to be more valid

5. Do the findings have practical relevance?

– Consider how the study is applied to real life situations

6. Ethical considerations