Bio Stats Previous Quizzes
which of the following is the strongest correlation?
-0.95
if the correlation between variables is 0.80, what is the coefficient of determination?
0.64 (take the value and square it)
for confidentiality, the researcher should
all of the above >make certain no unauthorized individuals have access to the research data >inform the participants about the people who will have access to the data >remove names from data-collection instruments and replace them with a code
which of the following shouldn't you calculate for nominal variables?
all of the above >median >standard deviation >mean
which of the following refers to a correlation between two variables?
bivariate
to predict one variable from another, you must first
compute the correlation
This type of research design involves examining relationships among variables, but does not involve manipulation of any variables.
correlational
____ approximates the sample size (adjusts the sample slightly to make for a more accurate outcome)
degrees of freedom
if you are trying to predict A scores from B scores, A is referred to as the ____
dependent variable
the numbers used to summarize characteristics of a sample is known as:
descriptive statistics
In evaluating the methods section of a research report, which is a very important question to keep in mind?
did the author provide enough information that the study could be repeated?
an index of the strength of the relationship among variables (a measure of the magnitude of the difference between groups) is the definition of:
effect size
what is the distance between each data point and the regression line called
error in prediction
"to what populations, settings, treatment variables, and measurement variables can this effect be generalized?" might most appropriately be asked in relation to
external validity
if a researcher increases the sample size in a study from 30 to 50, she is likely to decrease the power of her study
false
athletes' average mile time (6:51±0:52) was significantly faster than that of non-athletes (m=9:06±3:46)(p<.001). What type of t-test was used for this analysis?
independent t-test
a researcher conducts an experiment to examine the effect of exercise on memory. Exercise is the
independent variable
which of the following is NOT used to assess differences between data from two separate measurement from the same group?
independent-samples t test
the extent to which the results of a study can be attributed to the treatments used in the study is the definition of what kind of validity?
internal
a confidence interval defines the
interval that includes the population mean difference represented by the mean difference in our study
the coefficient of determination is the percentage of variance in one variable that ____
is accounted for by the variance in the other variable
a researcher wishes to study a group of children over a period of 10 years beginning in 2016 and ending in 2025. This is an example of a ____ study.
longitudinal
in a weight loss study you find that participants differ in amount of weight lose based on their gender. what type of effect is this?
main effect
which of the following is the appropriate measure of central tendency to report with an extremely skewed distribution?
median
In which section of a primary research article would you be most likely to find the following sentence: The items were rated on a 5-point Likert-type scale from rarely to usually and had demonstrated internal consistency (a=.88).
methods
to examine the impact of three different types of wall paint colors (blue, green, and yellow) on how often toddlers cry, which test is appropriate to use?
one-way ANOVA
the order in which runners finish a 5K race represents the ____ scale of measurement
ordinal
which of the following statements would appear in the procedures part of the methods section of a research report?
participants in the experimental group exercised three days per week for 30 minutes per day for 10 weeks
a ____ tells you what percentage of a distribution scored below a specific score
percentile
when variables change in the same direction, what type of correlation is this called
positive correlation
In which part of the methods section should you expect to find information about when the participants were tested?
procedures
the ____ is the distance between the minimum and maximum scores
range
which of the following is used to illustrate the best guess as to the predicted Y variable score based on X?
regression line
you are training for a 10K race and what to know if your running time is decreasing so you use your cell phone to time your runs which follow the same course each day. You find that your running times vary by more than 5 minutes and not always in the same direction. According to your cell phone, sometimes you go faster and sometimes slower. You begin to question the ____ of the stopwatch on your cell phone.
reliability
you are interested in finding out if students' achievement level changes over time as result of a reading intervention. what type of ANOVA would you use?
repeated measures
This question pertains to the following study: "A researcher wishes to determine the effects of an outdoor adventure summer camp on the self-concept of inner-city boys. Boys are randomly assigned to the summer camp and to a control situation. The experimental treatment is for three months. A secondary purpose is to see if age (ages 6, 9, and 12) affects the relationship of the camp effects and self-concept." The dependent variable is
self-concept
the ____ describes how much, in general, the scores in a sample differ from the mean
standard deviation
what does the number 5.15 represent in the following: t(42) = 5.15, p < 0.01?
t value
A pretest of knowledge about microcomputers is given to a group of students 5 minutes prior to a film on the subject. A posttest given 10 minutes after the film shows a 10-point gain from the pretest. The researcher concludes that the film produced the gain. Which of the following is likely the threat to internal validity?
testing
the correlation between the two variables of interest is 0.081, which is significant at the 0.637 level. this means ____
that you fail to reject the null hypothesis
in ANOVA, you have an interaction effect when ____
the effect of one independent variable differs based on the level of a second independent variable
increasing the sample size in a study from 30 to 50 increases the power of a study because
the larger sample size better represents the population and better represents any differences that exist in the population
when multiple t tests are performed, which of the following is TRUE?
the risk of Type I error increases
a descriptive study would NOT be appropriate to use to meet which of the following goals?
to determine a cause-and-effect relationship between variables
type I errors can be reduced by using a more stringent alpha level, such as p<.01
true
with an alpha set at .05 and the research hypothesis that CPR performance is better following a deliberate feedback intervention (p=0.12), you would reject the null hypothesis
true
what is another name for a factorial ANOVA
two-way ANOVA
Levene's test tells us if
we have violated our assumption of homogeneity of variance
in a 4x3 factorial design, how many levels of the second grouping factor are there
3
when interpreting F(2, 27) = 8.80, p < 0.05, what is the total sample size examined?
30
when running a t test for dependent means on a group of 54 individuals, the degrees of freedom will be ____
53
data points that vary greatly from the main cluster of your distribution are known as
outliers
in a study designed to assess the comparative effectiveness of two workbooks used in teaching students about laboratory procedures, the independent variables of the study would be
workbooks
when an experimenter states that the level of significance is the .05 level, he is setting the probability of committing what?
type I error
suppose the type of computer game (violent vs. scavenger hunt) really has an impact on players' aggression but you do not reject the null hypothesis. you have made a
type II error
