STATs Final Exam Review

interval scales of measurement...

have equidistant scales

a graphical display for grounded frequency distributions with continuous data is called a ________

histogram

If the value of the test statistic is in the rejection region, then

- p<.05 - the decision is to reject the null hypothesis - the value of the test statistic is larger than the critical value (all of the above)

a simple frequency distribution

-can be used to summarize group data -can be used to summarized ungrouped data -summarizes the frequency of scores in a given category or range (all of the above)

in a normal distribution, 50% of all data:

-fall above the mean -fall below the mean -fall above or below the mode (all of the above)

a researcher distributes frequencies into the following classes: absent, tardy, present. what type of data are distributed?

-nominal -qualitative -ungrouped (all of the above)

what is the value of SS (sum of squares) for the following population? population: 1, 1, 1, 5

12

which proportion is largest in a z-distribution?

The proportion of area between z = +1 and z = -1.

independent variable

_________ is the variable in an experiment that is manipulated between conditions being observed

sample statistic

a characteristic (usually numeric) that describes a sample is called a ______

+ or - 2.042

a researcher matched 30 participants on intelligence (15 pairs of participants), and then compared differences in emotional responsiveness to two experimental stimuli between each pair. for this test what are the critical values, assuming a two-tailed test at a .05 level of significance?

most behavior is believed to ________ a normal distribution

approximate

as sample size increases, the standard error of the mean _________

decreases

the procedure of converting a categorical variable to numeric values is called:

coding

a researcher records the number of votes for each of five candidates running for class president. based on her presentation the following results, what type of statistics did she use?

descriptive statistics

the sample variance is computed by dividing the SS by _____; whereas the population variance is computed by dividing SS by _____

df; N

a researcher tests whether the dosage level of some drug (low, high)causes significant differences in health. To do this, the researcher randomly assigns rat subjects to receive a low or high dosage of the drug and records health-related measures in both groups. the type of method described is:

experimental

three research methods common to research in the behavioral sciences are

experimental, quasi-experimental, and correlation

a method for testing a claim or hypothesis about a parameter in a population, using data measured in a sample, is called _______

hypothesis testing

a researcher measures the body temperature (in degrees Fahrenheit) of participants immediately before and immediately following sleep. temperature is on what scale of measurement?

interval

a researcher asks adult participants to rank their top five favorite songs from their childhood. based on the scale of measurement described, which measure of central tendency is most appropriate to describe these data?

mode

An animal researcher measures the number of times a rat presses a lever located at the right, center, and left of a cage for a food reward. What scale of measurement is the location of lever pressing?

nominal

An education counselor records the number of high school graduates enrolled in community colleges, four-year colleges, and universities. What scale of measurement is the type of college?

nominal

inferential statistics

procedures that allow researchers to infer or generalize observations made with samples to the larger population from which they were selected best describes_______

Recording whom students study with describes ________ types of data; whereas recording the number of hours spent studying per week describes ________ types of data.

qualitative; quantitative

three key elements of control that allow researchers to draw cause-and-effect conclusions are ________

randomization, manipulation, and comparison/control

to determine the interval width, we divide the _______ by the number of intervals

real range

a type of related samples design in which participants are observed more than once is called:

repeated measures design

a researcher measures the number of trials it takes two samples of participants to master a new task. in both samples, SS = 240. ample A consisted of 12 participants and sample B consisted of 18 participants. which sample is associated with the largest variance?

sample A

researchers measure data in a ________ to learn more about individuals in the larger _______ of interest

sample; population

a researcher conducts an experiment to determine whether moderate doses of St. Johns Wort have any effect on memory for college students. For this study what is the independent variable?

the amount of St. Johns Wort given to each participant

level of significance

the criteria for a decision regarding the value stated in a null hypothesis is set by

+ or - 2.086

the critical value(s) for a t test using a two-tailed test at a .05 level of significance: t(20)

which of the following best describes a dependent variable

the measured behavior

a researcher identifies college students as a group of interest to test her hypothesis. she then identifies a few local college students and selects a small group of the local college students to be observed. in this example, the sample is:

the small group of college students who were observed

a student scores in the 80th percentile on an exam. what does this mean in comparison to all other students?

the student scored higher than 80% of all other who took the exam

difference scores

the test statistic for a related samples t test makes tests concerning a single sample

.05

the typical level of significance for a hypothesis test in behavioral research

descriptive statistics

the use of tables and graphs to summarize data

Researchers rarely have access to entire populations. How do researchers resolve this limitation?

they record data from a sample of people in the larger population in order to make inferences concerning characteristics in that larger population

a measure of the average squared distance of scores from the mean is called the ____________

variance

a researcher records the following data for the number of dreams recalled during a night of sleep for 10 college students: 3, 2, 4, 4, 3, 1, 1, 0, 2, and 9. is the mean equal to the median in this example?

yes

the unit of measurement distributed along the horizontal axis of a standard normal distribution is referred to as a

z-score