Summer psych 302 final
How many effects can be tested when conducting a 2x2 Between-Subjects, One-Way ANOVA? a) 1; the effect of the EV on the DV b) 2; the effect of EV1 and EV2 on the DV c) 3; the effect of EV1, EV2, and the interaction between EV1 and EV2 on the DV d) 3; the effect of EV1, EV2, and EV3 on the DV
3; the effect of EV1, EV2, and the interaction between EV1 and EV2 on the DV
Why is it important to construct a sampling distribution that represents the results that are expected if the null hypothesis is true when performing a hypothesis test? a)A sampling distribution that represents the null hypothesis gives researchers a way of gauging the likelihood that their results could be due to sampling error (i.e., due to chance) b) The sampling distribution represents the likelihood that the researcher's alternative hypothesis could, in reality, be true c) Researchers do not need to construct sampling distributions because test statistics calculated based on sample data are usually pretty close to the corresponding population parameter d) The sampling distribution gives researchers a way of knowing with absolute certainty the true mean of the population from which the sample was taken
A sampling distribution that represents the null hypothesis gives researchers a way of gauging the likelihood that their results could be due to sampling error (i.e., due to chance)
Pearson's correlation coefficient (r) is a measure of the ______________ relationship between two variables. a) Linear b) Cubic c) Curvilinear d) Quadratic
a) Linear
Which of the following is NOT an assumption of conducting Pearson's correlational analysis? a) Nonlinear dependent variable b) Random sample c) Linearity d) Both variables are normally distributed in the population
a) Nonlinear dependent variable
The hypothesis that we actually end up testing when performing a statistical analysis is the hypothesis that states the expected result if: a) There is a large effect of the explanatory variable on the dependent variable b) The explanatory variable has no effect on (or no relationship with) the dependent variable c) There is a small effect of the explanatory variable on the dependent variable d) The explanatory variable has an effect (or relationship with) the dependent variable
The explanatory variable has no effect on (or no relationship with) the dependent variable
Due to variability among individuals' scores in a population, when a sample is collected from a population, the mean of the sample is often not going to be exactly equal to the mean of the population it was collected from. This discrepancy between the sample mean and the population mean that's due to completely random factors is called . a) Sampling Error b) Standard Deviation c) Effect Size d) Population variability
a) Sampling Error
Cohen's d expresses the size of an effect in terms of: a) The distance between means in standard deviation units b) The percentage of variability in a DV that can be accounted for by an EV c) The distance between means in the raw units in which the variables were measured d) The distance of an obtained sample mean from the mean of a sampling distribution that describes all possible means that could be obtained if the null hypothesis were true
a) The distance between means in standard deviation units
The best-fitting regression line is the one that does the best at minimizing a) The sum of the squared distances between each participant's actual score and the score predicted by the linear model b) The sum of the raw distances between each participant's actual score and the score predicted by the linear model c) The distance of the y-intercept from zero d) The variation of the slope from zero
a) The sum of the squared distances between each participant's actual score and the score predicted by the linear model
Why do we need statistical techniques for drawing inferences about populations from sample data? a)Sample data is easier to collect than population-level data because researchers have limited resources b)Population-level data is messy and difficult to organize c)Data collected in smaller samples is more valid d)Conducting calculations with sample data is simpler than with population data
a)Sample data is easier to collect than population-level data because researchers have limited resources
A researcher is interested in the effect of the size of an audience on how nervous public speakers get. The researcher recruits 30 participants. They randomly assign each participant to give a speech in one of the following conditions: in front of a small audience, in front of a medium audience, or in front of a large audience. The researcher then measures the participants' nervousness on a 7-point scale. What type of test should the researcher use to analyze the effect of audience size on nervousness? a) Repeated-Measures, One-Way ANOVA b) Between-Subjects, One-Way ANOVA c) Between-Subjects, Two-Way ANOVA d) Independent-samples t-test
b) Between-Subjects, One-Way ANOVA
The difference between a participant's actual score on the outcome variable and the score predicted by the best-fitting linear regression model is considered a) The y-intercept b) Error c) The slope d) Y prime
b) Error
Repeated-measures ANOVA is a more powerful test than between-subjects ANOVA because variability due to _____________ is partitioned out of the within-group variability. a) The treatment effect b) Individual differences c) The interaction effect d) The effect of the EV on the DV
b) Individual differences
The null hypothesis for a correlational analysis states that a) The correlation between the two variables being investigated in the population is not equal to zero b) The correlation between the two variables being investigated in the population is equal to zero c) The correlation between the two variables being investigated in the population is linear d) The correlation between the two variables being investigated in the population is nonlinear
b) The correlation between the two variables being investigated in the population is equal to zero
r2 expresses the size of an effect in terms of: a) The distance between means in standard deviation units b) The percentage of variability in a DV that can be statistically accounted for by an EV c) The distance between means in the raw units in which the variables were measured d) The distance of an obtained sample mean from the mean of a sampling distribution that describes all possible means that could be obtained if the null hypothesis were true
b) The percentage of variability in a DV that can be statistically accounted for by an EV
Which of the following is NOT an assumption for conducting a between-subjects, two-way ANOVA? a) Independence of Observations b) Homogeneity of Variance c) Heterogeneity of Populations d) Normally distributed dependent variable
c) Heterogeneity of Populations
While correlation is used for describing the linear relationship between variables, regression can be used to _______________ individuals' score on an outcome variable based on their scores on an explanatory variable. a) Cause b) Direct c) Predict d) Create
c) Predict
A researcher is interested in whether there is an effect of type of feedback on self-esteem. The researcher recruits 25 participants and gives each participant positive feedback on day 1, negative feedback on day 2, and neutral feedback on day 3. The participants' self-esteem is measured after each type of feedback is given. What type of test should the researcher use to analyze the effect of feedback on self-esteem? a) Independent-samples t-test b) Between-Subjects, One-Way ANOVA c) Repeated-Measures, One-Way ANOVA d) Paired-samples t-test
c) Repeated-Measures, One-Way ANOVA
In the equation used for modeling a regression line, Y = a + bX, "b" corresponds to the model's ________, and "a" corresponds to the model's ________. a) Actual score on the outcome variable; predicted value on the outcome variable b) Y-intercept; slope c) Slope; y-intercept d) Predicted value on the outcome variable; actual score on the outcome variable
c) Slope; y-intercept
__________________ refers to the branch of statistics that was developed to test hypotheses about populations from sample data. a) Sample statistics b) Descriptive statistics c) Inferential statistics d) Population statistics
c)Inferential statistics
Which step of hypothesis testing limits the chances of claiming that an effect exists when a result is actually due to sampling error (i.e., due to chance)? a)Stating the null and alternative hypotheses b)Stating the assumptions of the hypothesis test c)Specifying alpha when setting a decision rule d)Calculating the test statistic
c)Specifying alpha when setting a decision rule
A researcher follows the steps of hypothesis testing using an alpha of .05 to examine whether an EV has an effect on a DV. The results of the analysis are significant. Which of the following can the researcher NOT conclude solely based on the significant findings? a)The researcher can be reasonably confident that their results are unlikely due to sampling error b)The researcher can be reasonably confident that their results are unlikely due to chance c)The researcher can be reasonably confident that there is a moderate to large effect of the EV on the DV d)The researcher can conclude that there was a less than 5% chance of obtaining a test statistic as extreme as the one they found if the null hypothesis were true
c)The researcher can be reasonably confident that there is a moderate to large effect of the EV on the DV
A researcher wants to test whether children's math scores differ depending on whether they go to public or private school and whether they participate in extracurricular activities or not. The researcher recruits 60 children for their study. Each child either goes to public or private school and either participates in extracurricular activities or not. The researcher measures participants' scores on a standardized math exam. What type of test should the researcher use to analyze the effects of type of school and participation in extracurricular activities on math scores? a) Independent-Samples t-test b) Paired-Samples t-test c) Repeated-Measures, One-Way ANOVA d) Between-Subjects, Two-Way ANOVA
d) Between-Subjects, Two-Way ANOVA
A researcher wants to investigate whether a linear relationship exists between life satisfaction and charitable giving. The researcher recruits 100 participants and asks them to report their life satisfaction on a 7-point scale and the amount of money that they donated to charity this year. What type of test should the researcher use to analyze the relationship between life satisfaction and charitable giving? a) Independent-Samples t-test b) Between-Subjects, One-Way ANOVA c) Repeated-Measures, One-Way ANOVA d) Correlation
d) Correlation
Which of the following is NOT an assumption for conducting a repeated-measures, one-way ANOVA? a) Normally distributed dependent variable b) Independence of observations within conditions c) Random sample d) Independence of observations between conditions
d) Independence of observations between conditions
A researcher wants to test the effect of a newly developed medication on cold symptoms. The researcher recruits 50 participants. They randomly assign half of the participants to take the medication for a week, and the other half to take a placebo for a week. At the end of the week, the researcher measures the participants' cold symptoms. What type of test should the researcher use to analyze the effect of the medication on cold symptoms? a) Single Sample t-test b) Paired-Samples t-test c) Single Sample z-test d) Independent-Samples t-test
d) Independent-Samples t-test
A researcher analyzes the relationship between two variables using Pearson's correlation coefficient and gets an r value close to zero. When they inspect their data using a scatterplot, the pattern between the two variables looks like the following: Which potential issue with interpreting correlations is most likely contributing to the researcher's misleading result? (the graph has a peak) a) Outliers b) Restriction of range c) Underpowered d) Nonlinearity
d) Nonlinearity
Which of the following is the best description of what a 95% confidence interval is? a) The interval within which there is a 95% chance the true population mean lies b) The percentage of variability in a DV that can be accounted for by an EV c) The likelihood that the researcher can reject the null hypothesis d) One interval among many possible confidence intervals, where if the sampling process were repeated many times, 95% of these intervals would contain the true population mean, and 5% would not
d) One interval among many possible confidence intervals, where if the sampling process were repeated many times, 95% of these intervals would contain the true population mean, and 5% would not
1."Descriptive statistics" refers to a set of statistical techniques that are used to a)Test hypotheses about populations b)Measure the amount of sampling error in a population c)Draw inferences about a large group of people from a smaller subset of people d)Organize and describe a large amount of data to make it easier to comprehend
d) Organize and describe a large amount of data to make it easier to comprehend
A researcher comes across an article that conducted a national survey on cell phone use in the United States. The article says that, on average, Americans use their cell phones for 350 minutes a day. The article provides no other information. You want to compare the average amount of cell phone use of students at your university to the national average. What type of test should you use? a) Paired-samples t-test b) Independent-samples t¬-test c) Single Sample z-Test d) Single Sample t-Test
d) Single Sample t-Test
. Which of the following statements is true about how variability is partitioned when conducting a between-subjects, two-way ANOVA? a) The total variability is separated into variability due to sampling error and variability due to individual differences in the population b) The variability due to individual differences is partitioned out of the within-groups variability c) The between-groups variability is partitioned into variability due to individual differences and variability due to the treatment effect d) The between-groups variability is partitioned into variability due to the effect of the column EV, row EV, and the interaction between the row and column EVs
d) The between-groups variability is partitioned into variability due to the effect of the column EV, row EV, and the interaction between the row and column EVs
Which of the following is the best description of the correlation represented in the scatterplot below? (The plot is going down and to the right) a) Strong, negative linear correlation b) Strong, negative quadratic correlation c) Weak to moderate, positive linear correlation d) Weak to moderate, negative linear correlation
d) Weak to moderate, negative linear correlation
2. Which of the following are examples of descriptive statistic techniques? a) Mean b) Range c) Histogram d) Ungrouped frequency table e) All of the above
e) All of the above
What does alpha represent? a) The researcher's willingness to commit a Type I error b) The researcher's willingness to commit a Type II error c) The researcher's willingness to conclude that there is an effect when there is, in reality, no true effect d) The researcher's willingness to fail to conclude that there is an effect when there is, in reality, a true effect e) Both a and c f) Both b and d
e) Both a and c
A researcher tested the effect of listening to music and performing yoga on stress levels. They graphed their study's results using a bar graph. What types of effects do the results shown in the bar graph indicate may be present? a) A main effect of listening to music b) A main effect of performing yoga c) An interaction between listening to music and performing yoga d) a and b e) b and c
e) b and c
When can the researcher reject the null hypothesis? a) When the test statistic calculated based on the researcher's sample data lands in the rare zone of the sampling distribution b) When the test statistic calculated based on the researcher's sample data lands in the common zone of the sampling distribution c) When the test statistic calculated based on the researcher's sample data is more extreme than the test's critical value(s) d) When the probability of obtaining the test statistic calculated based on the researcher's sample data is less than alpha e) When the probability of obtaining the test statistic calculated based on the researcher's sample data is greater than alpha f) All of the above g) B, C, and E h) A, C, and D
h) A, C, and D
