Research method & design in I-O Psychology

Lecture 2 (Jan 28, 2002)Major ref: Riggio, Ch 2 (w/o appendix);

Supplementary reading: Spector, Ch 2 (p. 22-

31)

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Outline Social scientific research methods

goals and steps Major research designs

experimental and correlational designs Measurement of variables

observationalself-report

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Social scientific research methods I/O psychology is the science of human

behavior at work Involves systematic way to examine an

issue (Scientific methods) e.g., Does the employee re-training program

improve employability?

Intuition, experience -> subjectivity

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Steps in the research process 1- Formulation of the problem or issue

identify an area of interest identify a focus

E.g., Employee re-training program …. Improve employability? Used the most effective teaching method? Is the effect long lasting?

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Steps in the research process 2 - Generation of hypotheses

get the basics literature search; preliminary observations,

experience; interviews

Further narrow the focus to one statement - hypothesis - the supposed relationships among variables

An example:

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The re-training program improves people’s employability

Generating a hypothesis

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3 - Selecting the research designguide the actual collection of dataresearch settings

laboratory vs. field

two major designs Experimental or correlational others: case study; meta-analysis

Steps in the research process

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3 - Selecting the research designHow to select the design?

Experimental -

E.g., whether someone undergoes the re-training program Correlational -

E.g., age, IQ, no. of siblings, nationality

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4 - Collection of datasampling

who is qualified to be participants? where to locate the participants? random selection - equal chance of being

selected– e.g.,

may affect the generalizability of the results

Steps in the research process

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5 & 6 - data analysis and results interpretationuse appropriate statistical analysesmean, SD, correlation, regression, analysis

of variance

Steps in the research process

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Research designs Experimental design Independent variable (IV)

examines its effects on people e.g., re-training program; salary increase;

manipulated (varied) by the researcher e.g., absence/presence; amount; frequency

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Experimental design Dependent variable (DV)

the part of the person that is being affected employability; work performance; absenteeism;

weight loss; English proficiency

measured by the researcher reveal the effects of the IV

change in DV is presumed to be caused by the change in IV

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Exercise I think having a big meal before class makes people sleepy. The more books you read, the faster you can read. Will employees become more motivated if you threaten them? You will put on weight if you have food within 3 hours before you

sleep. Comparing to youngster who do not receive monetary incentive,

those who do are more likely to complete the spring board program.

I think no matter if you complete the spring board program or not, you will be offered similar number of jobs.

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Experimental design Case:

Ho: The probability of getting a job is higher for people who have taken the re-training program than those who have not.

IV: DV:Sample:

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Experimental design

Treatment gp

Control gp

Sample

Measurethe DV

Measurethe DV

Re-trainingprogram

No training

Compare the

difference

Implement the IV

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Experimental design

Treatment gp

Control gp

Assign people to treatment and control groups what if assignment is non-random? By application?

Sample

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Experimental design

Treatment gp

Control gp

RandomAssignment

Random assignment Assign people into treatment or ctl gp randomlyEqual chance of being assigned to either gpAims at

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Treatment gp

Control gp

Measurethe DV

Measurethe DV

Re-trainingprogram

No training

Implement the IV

The 2 groups are equivalent

The 2 groups begin to differ

RandomAssignment

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Experimental design

Treatment gp

Control gp

RandomAssignment

Measurethe DV

Measurethe DV

Re-trainingprogram

No training

Compare the

difference

Implement the IV

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Experimental design The difference in DV between the

treatment and ctl gp = effects of IV (the treatment/manipulation)

Strength

Weakness

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Correlational design All variables are measured as they

naturally occur No manipulation by researcher

No treatment or control groupNo random assignment

Examples: Effects of personality, weather, no. of sibling on… employability, absenteeism, English proficiency

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Correlational design Correlation between the two variables

Positive or Negative? Self-esteem - life satisfaction Job satisfaction - quit intention Senior year students - absenteeism Length of queue - waiting time for the next bus Birth order - extraversion

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Correlational design Strength

Weakness illustration: love reading comic - language

proficiency (-ve relationship)

How to select the design? (s.8)

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Measurement of variable Observational

Obtrusive - individuals know that they are being assessed E.g., assessment centre E.g., Weakness -

Unobtrusive - aware of the observer, but do not know that they are being studied E.g., one-way mirror, using video tape E.g.,

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Measurement of variable Self-report

obtain information from participants’own report, very popular

survey (paper-n-pencil, telephone, face-to-face) time and cost efficient, require less manpower

Weakness biased; memory error; concern for face, only

give socially accepted answers, etc..