PSYC1040 Research Design

One of the main differences between experimental and observational research is that in experimental research...

• the independent variable (IV) is measured.

• the dependent variable (DV) is measured.

• a causal relationship between the IV and the DV cannot be established.

• the IV does not vary.

• the IV is manipulated and controlled.

What is an operational definition?

• a theoretical concept

• a specification of how to measure or manipulate a variable

• a rule assigning numbers to a variable

• a measure of predictive validity

• a measure of reliability

A researcher is comparing the mental arithmetic ability of men and women. She recruits a group of elderly men and a group of young women. The researcher concludes that women have better arithmetic ability compared to men.

What is a confound of this particular research design?

• Age

• Gender

• Mathematical ability

• Time of day

• Age and mathematical ability

In experimental research, one of the effects of individual differences, such as intelligence, is to...

• increase variability in the DV

• decrease variability in the DV

• increase any effect of the IV

• decrease any effect of the IV

• decrease any effect of the IV; and increase any effect of the DV

The confounding effect of situational variables can be dealt with by...

• (A) holding them constant

• (B) balancing them across conditions

• (C) allowing them to vary at random

• (D) allowing them to systematically vary with the IV

• (A) + (B) + (C)

Twenty 5-year-old children (N = 20) are randomly allocated into two groups of 10, and placed in either a special reading program group or a normal reading group. After six months the two groups are compared on reading ability.

What are the independent and dependent variables?

• IV: Age

  DV: Height

• IV: Reading program

  DV: Reading ability

• IV: Time

  DV: Reading program

• IV: Height

  DV: Reading ability

• IV: Reading program

  DV: Time

In research, variability in the dependent variable can be influenced by

• The IV

• Individual differences

• Extraneous variables

• Measurement error

• All of the above

A good study must always have:

• reliability

• realism/relevance

• causal interpretability

• all of the above

• at least one of the above