Research methods in psychology worksheet with answers

Why should correlation not be taken as proof of causation?

1. ACorrelations are never statistically significant
2. BA third variable or reverse causation could explain the relationship
3. CCorrelation coefficients are always too weak to indicate any real relationship
4. DCorrelations can only be negative

In a matched pairs design:

1. AParticipants are randomly allocated with no matching
2. BThe same participants take part in all conditions
3. COnly twins can take part
4. DParticipants are paired on relevant characteristics and one of each pair goes into each condition

A Type II error occurs when a researcher:

1. AFails to reject a null hypothesis that is actually false
2. BUses the wrong statistical test
3. CMeasures the wrong dependent variable
4. DRejects a null hypothesis that is actually true, finding an effect that is not there

In a normal distribution, approximately what percentage of scores lie within one standard deviation of the mean?

1. A50%
2. B95%
3. C68%
4. D99.7%

In a correlation, r = 0.40. What proportion of variance in one variable is shared with the other?

1. A40%
2. B4%
3. C60%
4. D16%

Experimenter bias is reduced most directly by:

1. AUsing a one-tailed hypothesis
2. BUsing a larger sample
3. CUsing a researcher who does not know the hypothesis or conditions to collect data
4. DUsing only volunteers

A researcher measures the effect of noise on concentration. Participants in the noise condition happened to be tested in the morning and the quiet condition in the afternoon. What is the problem?

1. ATime of day is a confounding variable
2. BTime of day is the dependent variable
3. CThe data are at nominal level
4. DThe study has too many conditions

Which non-parametric test compares two related samples, such as before-and-after scores on an ordinal scale?

1. AIndependent t-test
2. BChi-square test of independence
3. CMann–Whitney U test
4. DWilcoxon signed-rank test