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 a variable

• A rule assigning numbers to a variable

• A measure of predictive validity

• A measure of reliability

A researcher compares the mental arithmetic ability of a group of elderly men to a group of young women. The researcher concludes that women have better arithmetic ability compared to men. What is the research design?

• Repeated measures

• Independent groups

• Quasi-experimental

• Correlational

• None of the above

Answer explanation

Since gender is a variable that cannot be changed or manipulated, but simply observed, this is an observational study and thus, quasi-experimental.

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

• Griddy skills

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

• Increase variability in the dependent variable

• Decrease variability in the dependent variable

• Decrease any effect of the independent variable

• Increase any effect of the independent variable

• Increase the independent, control, and dependent variables.

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

• holding them constant

• balancing them across conditions

• allowing them to vary at random

• allowing them to vary systematically

• all three - i.e., holding them constant; balancing across conditions; and allowing them to vary at random.

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 produced by:

• The IV

• Individual differences

• Extraneous variables

• Measurement error

• All of the above