Emma Cox
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Quiz on Psychological Research Methods Exam practice, created by Emma Cox on 24/06/2014.

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Psychological Research Methods Exam practice

Psychological Research Methods Exam practice

Question 1 of 47

1

The WAIS intelligence quotient (IQ) is normally distributed with a mean of 100 and a standard deviation of 15. I fan IQ between 85 & 115 is deemed normal, what percentage of the the general population would be considered normal?

Select one of the following:

  • 30%

  • 50%

  • 70%

  • 90%

Explanation

Question 2 of 47

1

In the four bivariate relationships given below, in terms of person-product moment correlations (r), the strongest relationship is one for which r is:

Select one of the following:

  • .69

  • -.70

  • -.10

  • .01

Explanation

Question 3 of 47

1

In correlational analysis, skewed variables are transformed to be normally distributed because:

Select one of the following:

  • this increases the relationship between variables

  • this decreases the relationships between variables

  • the removes the effect of influential points

  • this might invalidate the test

Explanation

Question 4 of 47

1

Which on of the following does not increase the power of a test of r between X & Y?

Select one of the following:

  • Standardising the scores of X & Y (Llinear transformation)

  • Adopting a larger Type 1 error rate

  • Conducting a one tailed test instead of two tailed

  • Increasing the magnitude of r

Explanation

Question 5 of 47

1

In clinical trials, it is ethnically responsible to use a sample size that is sufficient enough to detect an effect but not too large as to inconvenience the patient any longer than necessary. Which sample size should the research use to ensure that she has sufficient power?

Select one of the following:

  • N = 15 (power of .70)

  • N = 22 (power of .80)

  • N = 30 (power = .90)

  • N = 37 (power of .95)

Explanation

Question 6 of 47

1

In clinical trials, it is ethnically responsible to use a sample size that is sufficient enough to detect an effect but not too large as to inconvenience the patient any longer than necessary. Which sample size should the research use to ensure that she has sufficient power?

Select one of the following:

  • N = 15 (power of .70)

  • N = 22 (power of .80)

  • N = 30 (power = .90)

  • N = 37 (power of .95)

Explanation

Question 7 of 47

1

What is a type 1 error?

Select one of the following:

  • Accepting the null hypothesis when it is false

  • Rejecting the null hypothesis when it is true

  • Accepting the null hypothesis when it is true

  • Rejecting the null hypothesis when it is false

Explanation

Question 8 of 47

1

A scatterplot of the residuals is NOT used to check for:

Select one of the following:

  • normality of distribution of errors

  • the relationship between variables

  • a non-random distribution of the residuals

  • homogeneity of variance of errors

Explanation

Question 9 of 47

1

Which case will not be considered an influential in a regression of Y on X?

Select one of the following:

  • A case with a mean of X and a large Y

  • A case with a small X and a mean of Y

  • A case with a large X and a small Y

  • A case with a mean of X and a mean of Y

Explanation

Question 10 of 47

1

When a regression line is fitted to the data, the lack of fit is best described by:

Select one of the following:

  • A negative correlation coefficient

  • A random distribution of the residuals

  • A non-random distribution of the residuals

  • A small unstandardised regression coefficient

Explanation

Question 11 of 47

1

If the assumption of heteroscedasticity has been violated, the residual while display...?

Select one of the following:

  • A random distribution of the residuals

  • A curvilinear distribution of the residuals

  • A denser portion of residuals above the line

  • A fanning out of residuals to one side

Explanation

Question 12 of 47

1

In multiple regression, the effect size of the prediction is given by the:

Select one of the following:

  • multiple correlation coefficient

  • squared multiple correlation coefficient

  • sum of the squared beta coefficients

  • sum of the individual squared correlations between the independent variable and the dependent variable

Explanation

Question 13 of 47

1

In standard multiple regression where X1 & X2 are used to predict Y, the square of the multiple correlation (R2) is:

Select one of the following:

  • the sum of the correlations between Y and X1 and between Y and X2

  • the sum of the squared correlations between Y and X1 and between Y and X2

  • the proportion of variance in Y uniquely & jointly predicted by X1 & X2

  • the proportion of variance in Y uniquely & jointly predicted by X1 plus the proportion of variance in Y uniquely predicted by X2

Explanation

Question 14 of 47

1

In a standard multiple regression, X1, X2 & X3 were used to predict Y. The obtained F statistic had a probability of .001. The unstandarised equation of predicted Y was .8X1 + .4X2 + .3X3 + .5. The semi-partial correlations of X1, X2 & X3 were .15, .25 & .05 respectively. We can conclude that....

Select one of the following:

  • The set of predictors did not significantly predict Y

  • X1 is a stronger predictor of Y than X2 or X3

  • X3 alone would not significantly predict Y

  • X2 makes the best unique contribution to the prediction of Y

Explanation

Question 15 of 47

1

In a standard multiple regression of X1, X2 & X3 predicting Y, the tolerance value of X1 is the proportion of variance in X1 that is...

Select one of the following:

  • shared with X2 & X3 but not with Y

  • shared with Y but not with X2 & X3

  • not shared with X2 & X3

  • shared with X2 & X3

Explanation

Question 16 of 47

1

In a table of intercorrelations, predictor X1 had the highest, and statistically significant, correlation with Y (the dependent variable). Which one of the following statement is FALSE?

Select one of the following:

  • In a forward regression, X1 was not included in the final equation because its contribution was redundant to other predictors that entered the equation

  • In a backward regression, X1 was not included in the final equation because its contribution was redundant to other predictors that entered the equation

  • In a stepwise regression, X1 was not included in the final equation because its contribution was redundant to other predictors that entered the equation

  • In a hierarchical regression, X1 was not relevant to the hypothesis being tested

Explanation

Question 17 of 47

1

In a study that had collected initial weight, weight loss after training, motivation to lose weight, duration of training period, and amount of exercise, what is likely to be the dependent variable?

Select one of the following:

  • Weight loss after training

  • Motivation to loose weight

  • Duration of training period

  • Amount of excercise

Explanation

Question 18 of 47

1

In the study described in (2), which of the following regression methods would allow the most sophisticated test of a theory on weight loss?

Select one of the following:

  • Multiple regression

  • Hierarchical regression

  • Stepwise regression

  • Backward regression

Explanation

Question 19 of 47

1

In the study described in (2), if you were select a predictor to enter in the first step, which would you select?

Select one of the following:

  • Initial weight

  • Motivation to lose weight

  • Duration of training period

  • Amount of exercise

Explanation

Question 20 of 47

1

In a hierarchical regression predicting Y, predictors X1 and X2 as Subset A were first entered by the researcher, followed by predictors X3 and X4 as Subset B. Which one of the following statements is definitely true?

Select one of the following:

  • Predictors in subset A are not correlated with predictors in subset B

  • Predictors in subset A account for more variance in Y than predictors in subset B

  • Total R2 is the sum of the changes in R2 due to the entry of Subset A and Sunset B

  • Total R2 is the sum of the squared correlations between Y and each predictor

Explanation

Question 21 of 47

1

Which one of the following is most likely a polytomous variable>

Select one of the following:

  • Gender

  • Age

  • Marital status

  • Income

Explanation

Question 22 of 47

1

A researcher collected data on religious affiliation and involvement in gambling. Religious affiliation was a polytomous variable with four categories; namely, Christian, Buddhist, Muslim, and “No religion”. Three dummy variables (0,1), called Christian, Buddhist, and Muslim, were created to represent Christian, Buddhist, and Muslim affiliations, respectively. In a stepwise multiple regression to predict gambling, Christian and Buddhist were the two predictors selected. In interpreting the effect of Christian in this regression, which one of the following statements is definitely true?

Select one of the following:

  • C tests the effect of Christian versus Buddhist on gambling

  • C tests the effect of Christian versus Buddhist and Muslim on gambling

  • C tests the effect of Christian versus Muslim and “No religion” on gambling

  • C tests the effect of Christian versus “No Religion” on gambling

Explanation

Question 23 of 47

1

In a large sample (N = 500), removing a poor fitting case with a large standardized residual (i.e., ZRE_1) is likely to

Select one of the following:

  • Decrease R2 a little

  • Decrease R2 a lot

  • Increase R2 a little

  • Increase R2 a lot

Explanation

Question 24 of 47

1

The magnitude of the pearson product-moment correlation (r) between X & Y is not biased by:

Select one of the following:

  • size of the sample

  • non-normality in X

  • non-normality in Y

  • non-linearity of the relationship

Explanation

Question 25 of 47

1

The external validity of an experiment can by improved by:

Select one of the following:

  • using a representative sample of the population

  • holding constant the effect of nuisance variables

  • balancing the effect of nuisance variables

  • random assignment of participants to treatment groups

Explanation

Question 26 of 47

1

The external validity of an experiment can by improved by:

Select one of the following:

  • using a representative sample of the population

  • holding constant the effect of nuisance variables

  • balancing the effect of nuisance variables

  • random assignment of participants to treatment groups

Explanation

Question 27 of 47

1

Balancing nuisance factors (e.g., sex, age) neutralizes their potential effects on the internal validity of an experiment, but nuisance factors can still

Select one of the following:

  • decrease sensitivity and increase external validity

  • decrease both sensitivity & external validity

  • increase sensitivity & decrease external validity

  • increase both sensitivity & external validity

Explanation

Question 28 of 47

1

The defining characteristic of a true experiment is:

Select one of the following:

  • the high degree pf control in testing

  • the random assignment of subjects to experimental & control conditions

  • the operationalisation of dependent variables

  • the systematic manipulation of independent variables

Explanation

Question 29 of 47

1

A sample of 100 participants were randomly allocated into two equal-sized weight loss programmes - one that focussed on dieting and the other that focussed on exercise. At the end of 20 weeks of training, 32 participants remained – 20 in the dieting group and 12 in the exercise group. Results show that the weight lost by the dieting group was significantly less than that of the exercise group. A criticism of this experiment is that the findings may be biased by the effect of:

Select one of the following:

  • history

  • selection bias

  • attrition

  • regression to the mean

Explanation

Question 30 of 47

1

Use of control group, plus random assignment of participants to treatment, would allow us to avoid:

Select one of the following:

  • selection bias

  • attrition

  • experimenter bias

  • effects from testing

Explanation

Question 31 of 47

1

The ANOVA tests for differences between

Select one of the following:

  • variances of the groups

  • standard deviations of the groups

  • means of the groups

  • individuals of the groups

Explanation

Question 32 of 47

1

A statistically significant result means that the obtained probability (p) of the test statistic is

Select one of the following:

  • less than .05

  • equal to .05

  • greater than .05

  • greater than 1

Explanation

Question 33 of 47

1

If assumptions of the ANOVA are violated, the actual Type 1 error rate will...

Select one of the following:

  • be greater than a

  • equal to a

  • be smaller than a

  • be smaller of greater than a

Explanation

Question 34 of 47

1

A Brain Training software company claims that its 20-week training programme can increase a person’s IQ by five points. Given that the normative mean of IQ is 100, with a standard deviation of 15, the magnitude of the claimed effect is

Select one of the following:

  • negligible

  • small

  • medium

  • large

Explanation

Question 35 of 47

1

A Brain Training software company claims that its 20-week training programme can increase a person’s IQ by five points. Given that the normative mean of IQ is 100, with a standard deviation of 15, the magnitude of the claimed effect is

Select one of the following:

  • negligible

  • small

  • medium

  • large

Explanation

Question 36 of 47

1

Upon obtaining a significant F test result in an ANOVA comparing mean weekly gambling frequency of Catholics, Protestants and Non-Christians, what test(s) would you use to compare the group means?

Select one of the following:

  • the student t-test

  • the student newman keuls test

  • the tukey HSD test

  • the tukey kramer test

Explanation

Question 37 of 47

1

In between subjects ANOVA, the error term is the unexplained variance of the dependent variable. A second facotr when included in a one-way ANOVA, making it a two-way ANOVA, has the effect of:

Select one of the following:

  • controlling another source of variance, and increasing the error term

  • controlling another source of variance, and decreasing the error term

  • adding another source of variance, and increasing the error term

  • adding another source of variance, and decreasing the error term

Explanation

Question 38 of 47

1

In a two-way ANOVA, the number of possible F ratios is

Select one of the following:

  • 4

  • 3

  • 2

  • 1

Explanation

Question 39 of 47

1

When a significant F ratio is found for interaction in ANOVA of two factors (A & B) the next steps is to test:

Select one of the following:

  • main effect of factor A

  • main effect of factor B

  • simple main effect of A & B

  • association of A & B

Explanation

Question 40 of 47

1

A researcher performed a two-way between-subjects ANOVA - the p value obtained for the first factor (AGE) was .020, the p value obtained for the second factor (GENDER) was .060 and the p value for the interaction (AGE x GENDER) was .040. The most appropriate conclusion to make at this point, without further testing, is:

Select one of the following:

  • age is statistically significant and gender is not statistically significant

  • age is statistically significant under some level of gender

  • gender is statistically significant under some level of age

  • b or c, or both

Explanation

Question 41 of 47

1

Planned orthogonal contrast should be used:

Select one of the following:

  • for setwise comparison means

  • for pairwise comparison means

  • following a significant F in the oneway ANOVA

  • in place of the overall F test in ANOVA

Explanation

Question 42 of 47

1

The most conservative pairwise comparison between a set of four means is:

Select one of the following:

  • the t test

  • the scheffe test

  • the student newman keuls test

  • the tukey test

Explanation

Question 43 of 47

1

In a conventional experiment involving five planned comparisons, the bonferroni method would have a set error rate to:

Select one of the following:

  • <.01

  • .01

  • <.05

  • .05

Explanation

Question 44 of 47

1

Which of the following statements about a set of orthogonal contrasts between five groups is FALSE?

Select one of the following:

  • the coefficients of a linear contrast sum to 0

  • the cross products of coefficients of any pair of contrasts sum to 0

  • the can at most be five contrasts in the set of orthogonal contrasts

  • there are more than one set of orthogonal contrasts

Explanation

Question 45 of 47

1

In an analysis of covariance (ANCOVA) on the final weight of participants in a group focussing on diet and those in a group focussing on exercise, it is important to partial out the effect of:

Select one of the following:

  • initial weight

  • age

  • gender

  • group

Explanation

Question 46 of 47

1

In an one-way analysis of covariance (ANCOVA), there is the dependent variable (DV), the independent variable (IV), and the covariate (CV). The purpose of ANCOVA is to test:

Select one of the following:

  • differences between the IV on the DV that is not explained by the CV

  • differences between the IV on the CV that is not explained by the DV

  • differences between the IV on the DV and the CV

  • differences between the IV on the CV and the DV, after adjusting for each other

Explanation

Question 47 of 47

1

In within-subjects ANOVA, the Greenhouse-Geisser epsilon-correction procedure is employed to handle an untenable assumption about the

Select one of the following:

  • homogeneity of variances

  • homogeneity of covariances

  • independence of observations

  • normality of distribution of observations.

Explanation

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