Exam 3
Researchers try to ______ between-groups variance and ______ within-groups variance. A. minimize; minimize B. minimize; maximize C. maximize; minimize D. maximize; maximize
C
The value of Pearson's r ranges between ______. A. 0.0 and +1.0 B. -1.0 and 0.0 C. -1.0 and +1.0 D. 0.0 and 10.0
C
The regression equation is always represented by the formula ______. A. X' = Yb + X B. X' = bX + Y C. Y' = a - bX D. Y' = bX + a
D
A 95% confidence interval of 2.68 < µ1 µ2 < 5.79 tells us that we can be ______. A. 95% confident that the mean difference from the study represents a population of mean differences falling between 2.68 and 5.79 B. 5% confident that the mean difference from the study represents a sample of mean differences falling between 2.68 and 5.79 C. 95% confident that the mean difference from the study represents a population of mean differences falling outside of 2.68 and 5.79 D. we can only be confident of the confidence interval if our means fall between 2.68 and 5.79
A
A blind-experiment helps reduce ______. A. demand characteristics B. experimenter expectancy effects C. floor effects D. diffusion of treatment
A
A correlation coefficient provides two pieces of information about a relationship. They are the ______. A. strength and direction of a relationship B. direction and cause of a relationship C. strength and prediction of each variable D. direction and effect size of a relationship
A
A regression equation allows you to ______. A. more closely estimate the value of Y for a given X value B. make predictions of Y that match the actual values of y C. predict only the whole number values D. eliminate any error in the prediction of Y values
A
A researcher conducts a group design to determine the effect of Variable A on Variable B. The researcher can eliminate or control for the threats of history, maturation, testing, and instrumentation by ______. A. keeping everything, except Variable A, constant across groups B. including a pretest C. excluding any participants with extreme scores on Variable B D. using a confederate
A
A researcher conducts a study examining the effect of exercise on mood. She recruits participants from a health club to exercise for 30 min and then report their mood. She then recruits participants from a book club to sit for 30 min and then report their mood. Because the groups were different prior to the study, ______ is a threat to the study's internal validity. A. selection B. attrition C. history D. maturation
A
A researcher conducts a study in which he randomly assigns participants to either read a scenario about a man or about a woman. As a manipulation check, he might ______. A. ask participants to report the gender of the person described in the scenario B. ask participants to rate the scenario based on how vivid the description was C. observe participants reading the scenarios D. ask participants to rate the likeability of the person described in the scenario
A
A researcher designs an experiment with two groups. She decides to randomly assign participants to group by having each participant pull a number (1 or 2) out of a hat. What type of random assignment is this? A. simple random assignment B. stratified random assignment C. matched random assignment D. cluster random assignment
A
A(n) ______ is manipulated in an experiment. A. independent variable B. dependent variable C. pretest D. posttest
A
According to the null hypothesis for a simple experiment, we expect the difference between the means of our two groups to be ______. A. 0 B. 1 C. 10 D. very large
A
Ben is researching the effect of sleep deprivation on test scores. He finds a significant effect and computes the effect size of rpb2 = .15. This can be interpreted as meaning ______. A. 15% of the variability in test scores is accounted for by sleep deprivation B. 15% of the variability in sleep deprivation is accounted for by test scores C. just under 4% of the variability in test scores is accounted for by sleep deprivation D. just under 4% of the variability in sleep deprivation is accounted for by test scores
A
Correlational designs can have greater external validity than experiments because correlational designs ______. A. better represent the everyday world where we do not manipulate or control events B. study true relationships while experiments only manipulate relationships C. are more attractive to participants D. easier to conduct
A
Extreme scores tend to move closer to the mean over time. This is due to ______. A. statistical regression B. testing C. instrumentation D. maturation
A
If tobt = 1.98 and tcrit = 2.16, we would ______. A. retain the null hypothesis B. reject the null hypothesis C. retain the alternative hypothesis D. reject both the alternative and null hypotheses
A
If we find a perfect correlation, the standard error of the estimate would equal ______. A. 0 B. .25 C. 3.50 D. 6.50
A
If you are conducting a study and the lights go out, which of the following threats to internal validity now limits your study? A. history B. maturation C. selection D. attrition
A
If you hypothesize that Variable A will cause a change in Variable B, you must design a study so that Variable A comes before Variable B. This is to test that the relationship meets the criteria of ______. A. sequencing B. correlation C. ruling out alternative explanations D. none of these
A
In the regression equation, a = ______. A. Y-intercept B. slope C. regression coefficient D. correlation
A
In the regression equation, b = ______. A. slope B. Y-intercept C. correlation D. ordinal variable
A
Kyle is conducting an experiment on the effect of monitoring on unethical behavior during tests. One group has an identified TA monitoring the test while the other group has no obvious monitor in the room. As the students turn in their test, they are asked if there was a monitor in the room during the test. This is an example of a ______. A. manipulation check B. check on the sensitivity of an instrument C. confound due to the TA presence D. double-blind study
A
Levene's test tells us if ______. A. we have violated our assumption of homogeneity of variance B. our means are significantly different C. our IV has a significant effect on the DV D. the effect size is strong
A
One reason to use a correlational design is ______. A. when an experimental study would be unethical B. when it is possible to manipulate the variable(s) of interest C. to examine causality D. to increase internal validity
A
Random assignment is used in an experiment so that ______. A. the groups are as similar as possible prior to the IV manipulation B. the groups are as different as possible after the IV manipulation C. the groups are independent prior to the IV manipulation D. the groups are dependent prior to the IV manipulation
A
The assumptions for the independent samples t test include ______. A. an IV that is dichotomous, DV that is interval or ratio, independent groups, homogeneity of variance B. an IV that is interval or ratio, DV that is dichotomous, independent groups, normally distributed DV C. an IV that is interval or ratio, DV that is dichotomous, dependent groups, normally distributed IV D. an IV that is dichotomous, DV that is ordinal, dependent groups, homogeneity of variance
A
The effect size for an ANOVA is computed using ______. A. eta2 B. Cohen's d C. Levene's test D. point-biserial squared
A
The extent to which we can say that one variable caused a change in another variable is called ______. A. internal validity B. external validity C. reliability D. correlation
A
The formula for F is ______. A. treatment variance + error variance/error variance B. between variance - error variance/within variance C. within variance + error variance/between variance D. between variance + error variance/treatment variance
A
The interpretation of the results for quasi-experimental designs differs from that of an experiment because ______. A. quasi-experiments examine relationships while experiments examine causation. B. quasi-experiments examine causation between two variables while experiments examine causation between three or more variables. C. experiments involve the manipulation of a variable while quasi-experiments do not. D. experiments manipulate an IV while quasi-experiments manipulate a DV.
A
The pooled variance is the ______. A. combined and weighted variances of the two groups in a simple experiment B. average variance of the two groups in a simple experiment C. sum of the two variances of the two groups in a simple experiment D. unweighted variances of the two groups in a simple experiment
A
The presence of a confounding variable means that you have not ruled out which of the following criteria for causality? A. ruling out alternative explanations B. sequencing C. correlation D. association
A
The results of an ANOVA are typically presented as above in a ______, which in this case shows ______. A. summary table; no difference between four groups on cognitive awareness B. summary table; a significant difference between three groups on cognitive awareness
A
The scatterplot above shows a ______. (straight line up) A. perfect positive relationship B. strong positive relationship C. strong negative relationship D. perfect negative relationship
A
The standard error of the difference between means (SDX - X) represents the ______. A. average variability in a sampling distribution of differences between means B. average standard deviation of means C. an estimate of the standard deviation of two samples D. the combination of standard deviations from multiple studies
A
We select the critical value of r from the table of values based on the ______. A. df, criterion level, and type of alternative hypothesis (one- or two-tailed) B. type of alternative hypothesis and type of correlation computed C. df, criterion level, and scale of measurement of our variables D. type of correlation computed and criterion level
A
We want our computed r value to be ______ the critical value listed in the table in order for it to be significant. A. greater than B. less than C. equal to D. equal to N minus
A
What is one advantage of conducting a multiple independent-groups design over multiple simple experiments? A. decreasing the probability of Type I error and confounds B. increasing the internal validity C. decreasing efficiency because it requires more participants D. allowing for examination of linear relationships
A
When two variables move in the same direction together (both increase or both decrease), they will be ______. A. positively correlated B. negatively correlated C. not correlated D. perfectly correlated
A
Which of the following statements is correct? A. Correlation is a prerequisite for causation. B. If there is correlation there can be no causation. C. Causation does not mean correlation. D. Correlation and causation are the same.
A
A correlational design ______. A. describes the relationship between two variables B. Is a type of study that tests the hypothesis that variables are related C. determines causation between variables D. examines causal relationships between three or more variables
B
A double-blind experiment helps reduce ______. A. demand characteristics and diffusion of treatment B. demand characteristics and experimenter expectancy effects C. diffusion of treatment and experimenter expectancy effects D. floor and ceiling effects
B
A researcher conducts an experiment in which he randomly assigns one group to complete mood questionnaires in a red room and another group to complete the questionnaires in a blue room. What type of manipulation is this? A. physiological manipulation B. environmental manipulation C. instructional manipulation D. scenario manipulation
B
A researcher designs an experiment with two groups. She decides to randomly assign participants by first dividing participants based on gender. She then randomly assigns the males by having them pull a number out of a hat, and then does the same for the females. What type of random assignment is this? A. simple random assignment B. stratified random assignment C. matched random assignment D. random assignment to order of conditions
B
A(n)______ is a group design in which a researcher compares preexisting or naturally occurring groups that are exposed to different levels of a variable of interest. A. experiment B. quasi-experiment C. descriptive study D. correlational study
B
After a study, which assessed the anxiety of students before a Research Methods test, the researcher reports that all the students scored between 20 and 25 on the 25-point scale of anxiety. What problem might exist with the scale? A. floor effect B. ceiling effect C. the scale may be unreliable D. the scale does not appear to measure anxiety
B
Anne and Jack are examining variables related to self-control. Anne finds r = +.40 between percentage of salary saved and self-control while Jack finds r = .60 between impulsivity and self-control. Which variable is more strongly related to self-control? A. percentage of salary saved B. impulsivity C. neither variable is significantly related to self-control D. you cannot tell from the information provided
B
Correlational designs include a ______ instead of an IV and a ______ instead of a DV. A. predictor; estimated value B. predictor; outcome C. outcome; predictor D. estimated effect; estimated value
B
Giving a pretest might result in which of the following threats to internal validity? A. statistical regression B. testing C. instrumentation D. maturation
B
In a study of the effect of daily exercise on happiness suppose we found that happiness (rated on a 25-point scale) was significantly higher (p = .03) for a group that exercised daily (M = 21.50) than for a group that exercised once a week (M = 15.50). We could interpret the practical significance of this study as ______. A. weak because the happiness scores may not really represent the participants sense of happiness B. strong because the average happiness ratings are very different and we could assume that the participants would notice the different levels of happiness that the ratings represent C. strong because we found a statistical significance in the happiness ratings D. unimportant because the participants will probably not continue to exercise in the future
B
Natural changes that occur over time can be a threat to internal validity. This threat is called ______. A. statistical regression B. maturation C. selection D. attrition
B
One reason to prescreen participants is to ______. A. increase external validity B. ensure that the study is ethical C. increase heterogeneity of the sample D. ensure the study uses random assignment
B
Steps we can take to ensure that our DV is reliable and valid include ______. A. using a new scale that we have developed to avoid the problems with older established scales B. using more than one item to measure our DV C. presenting all information in person rather than automating the data collection D. introduce the study in a different manner for each participant
B
The ______ the correlation, the ______ the standard error of the estimate. A. weaker; smaller B. weaker; larger C. stronger; stronger D. stronger; larger
B
The assumption that variances in populations are the same is called ______. A. homogeneity of participant populations B. homogeneity of variance C. similarity of effects D. group homogeneity
B
The expected value of F if the null hypothesis is true is ______. A. 0 B. 1 C. 10 D. depends on the strength of the effect of the IV
B
The formula for the independent-samples t test is ______. A. MD/SDD B. M1 - M2/SDX - X C. M1 M2/SDD D. MD/SDX - X
B
The inferential statistic used to analyze two-group designs is called the ______. A. one-sample t test B. independent-samples t test C. independent correlation coefficient D. independent-samples ANOVA
B
The point-biserial correlation coefficient (rpb) is used to analyze the ______. A. correlation between variables measured on interval and ratio scales B. correlation between a dichotomous and an interval/ratio variable C. effect of a nominal variable on an interval/ratio variable D. effect of an interval/ratio variable on a nominal variable
B
The scatterplot above shows a ______. (clump, going upward) A. weak positive relationship B. strong positive relationship C. weak negative relationship D. strong negative relationship
B
The strength of the relationship is evident from ______ and the direction of the relationship is evident from ______ in a correlation coefficient. A. how close the correlation coefficient is to +1.0; the sign of the coefficient B. how close the correlation coefficient is to the absolute value of 1.0; the sign of the coefficient C. whether the correlation coefficient is positive or negative; the scatterplot D. the scatterplot; the combination of the variables predicted values
B
The three major types of designs with two independent groups are ______. A. correlational, simple multigroups, quasi-experiments B. correlational, quasi-experiments, simple experiments C. simple experiments, regression, quasi-experiments D. factorial, simple experiments, two-group experiments
B
There are ______ regression equations for two correlated variables. A. 1 B. 2 C. 3 D. 0
B
We can increase the power of a correlational study by ______. A. using measures with floor or ceiling effects B. using measures that are valid and reliable C. restricting the range of scores for each measure D. only using a very small random sample
B
When entering data to analyze a correlation, you should be careful to enter ______. A. all of the data in one column with all of the X values listed first, following by all of the Y values B. the data in pairs for each participant, with the X value in one column and the Y value in the next column on the same row C. all of the data in one column with the X value for each participant in one row followed by the Y value for that person in the next row; repeat this pattern for all participants D. the data in any order you wish as the computer will identify the X and Y values for each participant
B
When two variables move in opposite directions (one increases while the other decreases), they are ______. A. positively correlated B. negatively correlated C. not correlated D. perfectly correlated
B
Which of the following is one of the threats to internal validity due to participant characteristics? A. maturation B. statistical regression C. testing D. history
B
Which of the following variables could serve as an IV in an experiment? A. gender of participant B. instructions to participants C. participants' political views D. participants' intelligence
B
You find a correlation between creativity and academic honesty of r = .40. The coefficient of determination for this relationship is ______. A. .04 B. .16 C. .84 D. .64
B
You should compute a linear regression equation when you ______. A. compute a significant correlation between two variables B. find a significant correlation for two interval/ratio variables C. find a significant rpb D. have one dichotomous and one interval/ratio measure and a significant rpb
B
You want to examine the relationship between owning a house (yes - no) and income. You would compute a ______. A. Pearson's correlation coefficient B. point-biserial correlation coefficient C. regression equation D. multiple R
B
______ is when participants withdraw from a study. A. History B. Attrition C. Statistical regression D. Maturation
B
______ validity is a type of external validity that assesses the degree to which a study's findings generalize to real-world settings. A. Evolutionary B. ecological C. environmental D. extreme
B
A confidence interval defines the ______. A. variability we expect in a population whose variability equals the difference we found in our study B. span of differences expected in a population whose variability is equal to our sample standard deviations C. interval that includes the population mean difference represented by the mean difference in our study D. mean difference between our sample and the population means
C
A multiple independent-groups design examines the effect of ______. A. more than one IV on a DV B. one IV on three or more DVs C. one IV with three or more levels on a DV D. two or more IVs on two or more DVs
C
A one-group pretest posttest design is subject to which of the following threats to internal validity? A. statistical regression, selection, attrition, history, maturation, testing, and instrumentation B. statistical regression, selection, history, maturation, testing, and instrumentation C. statistical regression, history, maturation, testing, and instrumentation D. statistical regression, history, and maturation
C
A researcher conducts an experiment examining the effect of a medication on anxiety. A control group would receive ______. A. no compensation for their time B. no informed consent C. no medication D. no posttest
C
A researcher conducts an experiment in which she randomly assigns one group to listen to directions and another group to read directions. What type of manipulation is this? A. physiological manipulation B. environmental manipulation C. instructional manipulation D. scenario manipulation
C
A researcher conducts an experiment to examine the effect of exercise on memory. Memory is the ______. A. Confound B. placebo C. dependent variable D. independent variable
C
A researcher hypothesizes that A causes B. He gives all participants a pretest to assess Variable B, then exposes them to Variable A and then gives them a posttest to assess Variable B. What type of design is this? A. experimental B. descriptive C. one-group pretest posttest D. two-group pretest posttest
C
A study that manipulates a variable under two conditions, randomly assigns participants to one of those two conditions, and measures its effect on another variable while controlling all other conditions is called a ______. A. correlational design B. quasi-experiment C. simple experiment D. multiple-groups experiment
C
A variable that varies systematically with the variables of interest in a study and is a potential alternative explanation for causality is called a(n) ______. A. independent variable B. dependent variable C. confound D. placebo
C
After computing a correlation, we compare our computed r value to the critical values for Pearson's r using ______ degrees of freedom. A. n B. n - 1 C. n - 2 D. it depends on whether we have a one- or two-tailed test
C
Confounds that must be controlled so that a cause effect relationship can be demonstrated are called ______. A. independent variables B. dependent variables C. threats to internal validity D. causality
C
Correlation is the statistic used to assess ______. A. causation between two interval/ratio variables B. relationships between two ordinal/ratio variables C. the validity and reliability of measures D. the lack of significant results
C
Degrees of freedom in for an independent-samples t test is computed by ______. A. df = N - 1 B. df = n1 + n2 - 1 C. df = (n1 - 1) + (n2 - 1) D. df = (n1 + 1) - (n2 + 1)
C
In a simple experiment examining the impact of violent games on aggressive thoughts, we might have participants play a violent game for 45 min rather than 5 min. This decision reflects our attempt to maximize power by ______. A. controlling conditions in our experiment B. ensuring that our IV is valid and reliable C. using a strong manipulation of our IV D. using similar participants in our study
C
Shawn examines the relationship between creativity and academic honesty and finds the coefficient of determination equals .33 or r2 = - .33. This means that ______. A. he has found a moderate correlation between the two variables B. he has found a strong correlation between the two variables C. 33% of the variability in academic honesty is accounted for by knowing its relationship with creativity D. 67% of the variability in academic honesty is accounted for by knowing its relationship with creativity
C
The Hawthorne effect is ______. A. an experiment in which the participants know they have been assigned to one particular IV condition but they do not know which one B. a treatment or substance that in and of itself has no therapeutic effect, such as a sugar pill C. a phenomenon in which participants change their behavior simply because they are in a study and have the attention of researchers D. a phenomenon in which a researcher unintentionally treats the groups differently so that results support the hypothesis
C
The average error between predicted Y values and the actual Y values is called ______. A. line of best fit B. standard error of the correlation C. standard error of the estimate D. estimated standard error of the estimate
C
The line of best fit represents ______. A. predictions of all the nominal variable values B. the best values for the measures C. the predicted Y values (Y') for each X value in the sample range D. the actual X and Y values for your sample
C
The one-way ANOVA compares ______. A. within-group variance for each group to within-variance for the total group B. error variance for each group to error variance for the total group C. between-groups variance and within-groups variance D. error and within-groups variance
C
The process of verifying that the participants attended to the manipulation is called a(n) ______. A. historical effect B. environmental manipulation C. manipulation check D. experimenter expectancy check
C
The sampling distribution for an independent-samples t test is a distribution of the differences between _____. A. sample and a population mean B. a population mean and the means of the two groups in our study C. the means of the two groups in our study D. the population means for the two groups in our study
C
The statistic used to determine whether a linear relationship exists between two interval/ratio variables is the ______. A. Cohen's d B. Y' determined by a regression equation C. Pearson's r D. multiple r
C
To determine where our mean difference falls on the sampling distribution that predicts no difference we need to know the standard deviation of the sampling distribution. This term is called ______. A. standard error of the means B. standard error of the estimate C. standard error of the difference between means D. standard deviation of the samples
C
We should not compute a regression equation if we do not find a significant correlation between two variables because ______. A. we need to correct errors in our data B. we can only compute regression equations when variables are causally related C. there will be too much error in our predicted values D. the slope of the regression equation would be flat
C
What is one of the key characteristics of a dependent variable measure? A. internal validity B. external validity C. sensitivity to change D. a ceiling effect
C
You believe that students anxiety is related to test scores in Research Methods. Which of the following represents a directional alternative hypothesis for your study? A. There is no relationship between student anxiety and test scores in Research Methods. B. There is a relationship between student anxiety and test scores in Research Methods. C. Students anxiety will be negatively related to their test scores in Research Methods. D. Student anxiety causes low grades in Research Methods.
C
A researcher conducts a one-group pretest posttest design. The researcher administers the pretest but has a colleague administer the posttest. ______ is a threat to the study's internal validity. A. History B. Maturation C. Testing D. Instrumentation
D
A researcher conducts an experiment to examine the effect of exercise on memory. Exercise is the ______. A. confound B. placebo C. dependent variable D. independent variable
D
A researcher wants to examine the effect of violent computer games on verbal aggression. She has college students play 45 min, 30 min, 15 min, or no minutes of a violent computer games. Which of the following best represents a nondirectional alternative hypothesis for this study? A. Ha: µ45min > µ30min > µ15min > µ0min B. Ha: µ45min = µ30min = µ15min = µ0min C. Ha: There will be no difference in verbal aggression after playing 45 min, 30 min, 15 min of no minutes of a violent computer game. D. Ha: There will be a difference in verbal aggression after playing 45 min, 30 min, 15 min of no minutes of a violent computer game.
D
An educational researcher randomly assigns 20 health classes to either receive a violence prevention curriculum for 5 weeks or to receive the usual health curriculum during the five weeks. What type of random assignment is this? A. simple random assignment B. stratified random assignment C. matched random assignment D. cluster random assignment
D
Assumption for a one-way independent samples ANOVA include ______. A. at least one IV with three or more levels B. DV is ordinal scale C. variability in each sample significantly differs D. groups are independent
D
Della wants to predict self-control scores using education level, impulsivity, and organizational skills as self-reported by students. She should compute ______. A. Pearson's r B. point-biserial correlation (rbp) C. coefficient of determination D. multiple regression
D
Diffusion of treatment occurs when ______. A. the researcher does not manipulate the IV consistently B. the treatment effects are measured similarly across the groups C. a researcher unintentionally treats the groups differently so that results support the hypothesis D. the treatment administered to one group is shared with another group through cross-group interactions
D
If a researcher conducts a dependent-groups experiment in which the participants experience all levels of the independent variable (IV), what type of random assignment should he use? A. simple random assignment B. stratified random assignment C. matched random assignment D. random assignment to order of conditions
D
In a simple experiment, the IV is on a ______ scale of measurement and the DV is on a ______ scale. A. nominal; ordinal or ratio B. ordinal; ratio or interval C. interval or ratio; nominal D. nominal; interval or ratio
D
Jesse is studying the effect of daily exercise on happiness. His directional alternative hypothesis might state ______. A. there will be no effect of daily exercise on happiness B. there will be an effect of daily exercise on happiness C. daily exercise will not affect happiness D. daily exercise will increase happiness
D
One reason that correlational designs do not establish causality is ______. A. there is too much control over the variables and context B. correlational designs never examine groups C. the variables are always interval or ratio scales of measurement D. a third variable could be responsible for the relationship between our variables
D
Someone who is working with the researcher but pretends to be a participant or bystander is called a ______. A. Confound B. placebo C. scenario manipulation D. confederate
D
The effect size for an independent-samples t test can be assessed using a(n) ______. A. eta squared B. coefficient of determination C. correlation squared D. point-biserial correlation squared
D
The inferential statistic used to analyze a multiple independent-groups study is ______. A. multiple independent-groups t test B. one-way multiple groups t test C. one-way ANALVAL D. one-way ANOVA
D
The mean square within groups represents the ______. A. average deviation of each participant s score from the population mean B. average deviation of group means from the population mean C. average deviation of group means from the total mean of the sample D. average deviation within all groups of the study
D
The post hoc test above shows that ______. A. there are no differences between the group means for happiness B. we do not know if the groups differ without applying the Bonferroni correction C. Group 3 significantly differs from Group 1 but not from Group 2 D. Group 2 significantly differs from Groups 1 and 3 which do not differ
D
The process of identifying those who have characteristics that the researcher wants to include or exclude in the study is called ______. A. manipulating the variables B. a quasi-experiment C. a pretest/posttest design D. prescreening
D
The results above suggest there is a probability of ______. A. a Type II error B. 5% for Type I error C. neither a Type I nor a Type II error D. 1.3% for a Type I error
D
The scatterplot for a perfect correlation would show ______. A. a horseshoe-shaped pattern B. a zigzag line C. points all over the graph with no pattern D. a straight line
D
The statistic that describes the proportion of variability that is accounted for by knowing the relationship between two variables is the ______. A. coefficient of prediction B. standard error of the estimate C. estimated standard error of the means D. coefficient of determination
D
Which of the following is one of the threats to internal validity due to experiences or environmental factors? A. statistical regression B. attrition C. diffusion of treatment D. instrumentation
D
You believe that students anxiety is related to test scores in Research Methods. The alternative hypothesis stated in numerical terms would appear as ______. A. Ho: r = 0 B. Ho: r ≠ 0 C. Ha: r = 0 D. Ha: r ≠ 0
D
