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PSYC210 Midterm Practice Questions
Let's say we wanted to use the Beck Depression Inventory to assess and diagnose depression. The BDI would be an example of: A) A Variable B) A Measurement Instrument C) Data D) Internal Validity - A measurement instrument If we wanted to determine if my PSYC210 class performed significantly better than another section on a statistics knowledge test, we would use: A) Descriptive statistics B) Inferential statistics C) Continuous statistics D) Discrete statistics - Inferential statistics What type of scale would I use if I wanted to measure your satisfaction with this course on a scale from 1, not very satisfied, to 7, very satisfied? A) Nominal B) Ordinal C) Interval D) Ratio - Ordinal or ratio
In this week's homework assignment, we are examining stress and drinking behavior in a college student sample. Stress and drinking behavior are: A) Variables B) Measures C) Data D) None of the above - Variables In a positively skewed distribution, what order (left to right) will you find the mean, median, and mode? A) Median, Mode, mean B) mean, mode, median C) Mean, median, mode D) Mode, median, mean - Mode, Median, Mean If I said you scored in the 72nd percentile, what percent of individuals would have scores lower than yours? A) 72% B) 28% C) Unable to tell without additional information - 72% The percentile formula can be used to: A) Determine at what percentile a given score falls B) Determine the score that would fall at a given percentile
A) Individual scores B) Population parameters C) Sample statistics D) Range - Sample statistics (i.e., the mean) The Central Limit Theorem posits that as N gets larger.... A) The distribution of a given variable's means will become normal. B) The distribution of a variable will be skewed positively or negatively C) The distribution will start to approximate the population distribution. - The distribution of a given variable's means will become normal. The ___ is the standard deviation of the sampling distribution. A) Standard deviation B) Sampling mean C) Standard error of the mean D) Population variance - Standard error of the mean Why is the standard error of the mean smaller than the standard deviation? A) Because we divide by the square root of N B) Because we have more information C) It is not smaller than the SD D) SE and SD will always be about the same. - Because we divide by the square root of N
How do I make statistical decisions (inference)? A) Examine a given value and compare it to 0. B) Examine a given value and compare it to a critical point. C) Examine the relative standing of a mean D) Examine the means and standard deviations - Examine a given value and compare it to a critical point Hypothesis testing allows us to: A) Determine if a difference is due to more than chance B) Determine if a sample is likely drawn from a given population. C) Determine the relative standing of a sample mean. D) Make decisions about samples. - Determine if a difference is due more than chance If I fail to reject the null hypothesis, what am I saying? A) Any difference I found was likely due to chance B) Any difference I found was real (unlikely due to chance) C) I have proven my sample is different from my population D) I have disproved my sample is from my population - Any difference I found was likely due to chance Type I Error is defined as A) Alpha B) Beta -
a. reject the null hypothesis (this difference is unlikely chance). b. fail to reject the null (this is due to chance likely) c. reject the null (this difference is likely chance). d. fail to reject the null hypothesis (this difference is unlikely chance). - reject the null hypothesis (this difference is unlikely chance) Levene's Test assesses ____. a. equality of variances b. homoscedasticity c. correlated differences d. independent differences - equality of variances In the regression equauation y=bx+a+e, "e" represents...? a. the y intercept b. the slope of the line c. differences between observed and predicted scores. d. predicted outcome scores. - differences between observed and predicted scores. The unstandardized regression coefficient known as "b" is: a. the slope of the line between x and y. b. in Y score units c. in X score units d. the X intercept -
the slope of the line between X and Y What test is used to determine the significance of the slope? a. Z-test b. t test c. anova d. chi-square - t-test What is the primary purpose of learning about statistics? a. so you can make a claim and support it with evidence b. to show discuss what kind of distribution you have. c. to learn the purpose of a standard normal distribution. d. so you can overwhelm your opponents with numbers - so you can make a claim and support it with evidence What do we mean when we use the term "variable" in statistics? a. the way we measure an abstract concept. b. an orderly way to assign numbers to observations. c. coding characteristics of human behavior into discrete categories. d. label that refers to some abstract concept that might differ between people. - label that refers to some abstract concept that might differ between people. Assessing how happy UNC students are on a 7-point scale (1-not happy to 7-extremely happy) would be best achieved using what type of scale?
d. nominal - ordinal For a relative frequency histogram, each point on the graph represents: a. the percent of scores at a particular point or interval. b. the percent of scores above a particular point or interval. c. the percent of scores at or below a particular point or interval divided by the total number of scores. d. the percent of scores above a particular point or interval divided by the total number of scores. - The percent of scores at a particular point or interval The heights of the columns of a histogram indicate the a. number of scores in a particular interval. b. the midpoints of the various intervals c. value of the score being graphed d. average scores - number of scores in a particular interval What is one way to simplify variables with many, many levels (or decimal places) when creating a frequency distribution: a. ignore outliers b. graph each level of the variable individually c. organize data into class intervals d. compute mean, median, mode - What is the purpose of a pie chart, histogram, or polygon?
a. to see what your distribution looks like before performing any statistical tests. b. to visually display otherwise confusing numbers. c. to utilize current technology to present relevant statistics. d. both A and B - both A and B When would the median be the most effective way to describe a distribution? a. when the mean, median, and mode are the same and you have a categorical variable. b. when data are continuous and the distribution is skewed by outliers. c. when the mean, median, and mode are the same and you have a continuous variable. - When data are continuous and the distribution is skewed by outliers Kurtosis refers to a. whether the distribution is continuous or discrete. b. the average distance of scores from a measure of central tendecy. c. the peakedness or flatness of a distribution. d. whether more extreme scores are in one tail of the distribution as opposed to another. - the peakedness or flatness of a distribution Why is the mean the most commonly used measure of central tendency? a. it gives us one, simple number that minimizes deviations overall. b. it isn't the most commonly used c. The median and the mode don't tell us much when variables are discrete. d. The mean is more appropriately used to describe variablility. - It gives one, simple number that minimizes deviations overall
b. the mean of the population distribution gets larger. c. the sample size gets larger. d. the sample distribution skews positively positively or negatively. - the sample size gets larger The process of selecting a subset of people from a population such that every person in the population has an equal chance of being chosen for the subset is called: a. standardizing the population. b. stimulus sampling c. random sampling d. population sampling - random sampling A researcher is curious about the average IQ of all currently registered voters in the state of Iowa. If this average could be obtained, it would be an example of a... a. population b. parameter c. sample b. statistic - parameter In addition to telling us at what percentile a given score or mean falls, z-scores tell us... a. our results are likely just due to chance. b. how extreme the difference is c. we have proven that our data is different from the population d. we have disproved that our data is different from the popilation -
how extreme the difference is A researcher says that her analysis shows that the effect of the independent variable on the dependent variable is statistically significant. This means that the effect is. a. very unlikely to occur by chance. b. very unlikely to be large c. very likely to be predictable d. very likely to be found again upon replication - very unlikely to occur by chance In hypothesis testing, a Type I Error is: a. rejecting the null hypothesis when the null hypothesis is false. b. rejecting the null hypothesis when the null hypothesis is true. c. failing to reject the null hypothesis when the null hypothesis is false. d. failing to reject the null hypothesis when the null hypothesis is true. - rejecting the null hypothesis when the null hypothesis is true In hypothesis testing, a Type II error is: a. rejecting the null hypothesis when the null hypothesis is false. b. rejecting the null hypothesis when the null hypothesis is true. c. failing to reject the null hypothesis when the null hypothesis is false. d. failing to reject the null hypothesis when the null hypothesis is true. - failing to reject the null hypothesis when the null hypothesis is false. In hypothesis testing, power is defined as the probability of:
d. heterogeneity of variance - homogeneity of variance What type of test is most appropriate when you want to compare an outcome between the same people at two different time points? a. regression and correlation analysis b. correlated samples t-test c. independent samples t-test d. t-test for correlations - correlated samples t-test What type of test is most appropriate when you want to compare an outcome between groups with different people in each group? a. regression and correlation analysis b. correlated samples t-test c. independent samples t-test d. t-test for correlations - independent samples t-test Whys is regression analysis so important in the social sciences? a. because it gives us an exact outcome for a given predictor b. because it allows us to predict important outcomes. b. because it has no variance c. because it uses both means and standard deviations - because it allows us to predict important outcomes
Mode is a measure of: a. skewness b. central tendency c. kurtosis d. variability - central tendency What is the primary purpose of graphing data? a. to perform complex statistical tests. b. to get a "lay of the land" and see what the data looks like c. to make sure you have a normal distribution d. to confuse consumers who may be interested in your data - to get a "lay of the land" and see what the data looks like Relative frequency could be better conceptualized as a. missing data b. total c. sum of all points before a certain number d. percent - percent What is the exact middle point of a distribution? a. median b. mean c. standard deviation
b. the right - the left What can you do to make the distribution with a lot of different numbers make sense? a. use confidence intervals b. omit needless data c describe it in words d. use class intervals - use class intervals How would you describe cumulative frequency in one word: a. dividing b. listing c. adding d. subtracting - adding If I was interested in measuring your political party affiliation, what scale would be best? a. interval b. ordinal c. nominal d. ratio - nominal Amount of money donated to charity would be best measured with a ___ scale?
a. nominal b. ordinal c. ratio d. interval - ratio If I asked you to rank your top ten favorite movies, I'd use a ___ scale. a. ratio b. ordinal c. nominal d. interval - ordinal What is the one reason we might care about cumulative frequency? a. to see what percent fall at that interval. b. to see if we have missing data. c. to determine what type of analysis we will use. d. to decide what type of scale we would use - to see if we have missing data What type of distribution is long and flat? a. leptokurtic b. platykurtic c. mesokurtic d. something else - platykurtic
