PSYC 4603 Statistics and Research Methods I, Chapters 1-8

Which type(s) of frequency distribution graph(s) should be used for data that come from a nominal scale of measurement?

Bar graphs

Which of the following is a requirement for a random sample?

Every individual has an equal chance of being selected, they probabilities cannot change during a series of selections, and there must be sampling with replacement.

Under which circumstance in a very small treatment affect still be statistically significant?

If the sample size (n) is very large

A researcher assesses eyecolor for a sample of n = 50 people. Which measures of central tendency would be appropriate to summarize the measurements of eyecolor collected for the sample?

Mode

A distribution of scores is positively skewed. Which is the most probable order, from smallest to largest, for the three measures of central tendency?

Mode, median, mean

The mode is the only measure of central tendency that is appropriate to utilize for a variable measured with which scale of measurement?

Nominal

Which statement accurately describes the proportions in the tales of a normal distribution?

Proportions in both tails are the same

For a research study examining how participant gender influences support for a quality in society, participant gender is an example of which kind a variable?

Quasi-independent variable

In order to facilitate independent random sampling, _______ must be utilized.

Sampling with replacement

In order to determine if 10 points below the mean on an exam is an extreme negative score, the _________ needs to be known.

Standard deviation

What additional information is obtained by measuring two individuals on an ordinal scale compared to a nominal scale?

The direction of the difference

A researcher chooses to collect data from a large sample that represents a population instead of a smaller sample. Which of the following is not a likely consequence of choosing to collect data from a large sample relative to a smaller sample?

The expected value of M will decrease.

A researcher conducts a study to examine how mental fatigue influences frustration levels. He has one group of participants complete a mentally exhausting problem-solving task for 10 minutes, and a second group of participants complete an easy crossword puzzle for 10 minutes. Then, he observes participant reactions to being prevented from achieving a desired goal on a second unrelated task as a measure of frustration levels. In this research study, the experimental condition is

The group of participants who complete mentally exhausting problem-solving task

Which of the following is not a unique advantage of the interquartile range as measure variability?

The interquartile range can be used for data measured with a ratio scale of measurement.

A researcher is measuring the amount of time needed to solve a set of anagrams for a sample of n = 15 students. However, one of the participants fails to solve the problems so the researcher has an undetermined score. What is the best measure of central tendency for these data?

The median

What is the preferred measure of central tendency of her score is measured on an ordinal scale?

The median

what additional information is obtained by measuring to individuals on an interval scale compared to an ordinal scale?

The size of the difference

A researcher selects a sample and administers a treatment for anxiety to the individuals in the sample. If the sample is used for a hypothesis test, what does the alternative hypothesis (H1) put forth about the treatment?

The treatment has an effect on anxiety

What is the effect of decreasing the Alpha level?

This action increases the likelihood of failing to reject H0 and increases the risk of a type two error.

Which of the following statements about the comparison between effect size and power is correct?

as effect size increases, power also increases

The amount of time that it takes a person to solve a problem as an example of a(n) __________ variable.

continuous

Why do you deviation scores have to be squared before calculating the standard deviation?

if deviation scores are not squared, then the average distance from the mean will always equal zero.

inferential statistics allow researchers to

make predictions and generalizations about populations

which of the following is a critical unique aspect of the experimental method when examining the relationship between two variables?

manipulation of one variable

A researcher uses an anonymous survey to investigate the television-viewing habits of 100 American adolescents. The researcher plans to make an inference about the television-viewing habits of all American adolescents based on the results of the survey. The entire group of American adolescents is an example of a

population

What scale of measurement is being used one a researcher measures the amount of car accidents that participants have been involved in during their lifetime?

ratio

A researcher uses an anonymous survey to investigate the social media habits of American college students. Based on the set of 300 surveys that were completed and returned, the researcher finds that students spend an average of 2 hours each day using social media. The set of of 300 students who returned surveys is an example of a

sample

Which of the following accurately describes the critical region?

sample means that are very unlikely to be obtained if the null hypothesis is true

The average verbal SAT score for the entire class of incoming college freshman in the United States is 530. However, if a sample of 20 incoming college freshman is randomly selected from the United States, it is likely that the samples average verbal SAT score will not be exactly 530 this is consistent with the concept of

sampling error

Which of the following characteristics tends to increase the likelihood that it clear difference between to sample means is detected statistically?

small variances within each sample

The motor is similar to the median as a measure of central tendency in that

there are no symbols used to differentiate between whether its value(s) pertains to populations or samples

If sample variance were to be computed by dividing SS by n, then the average value of the sample variances from all the possible random samples would consistently _________ the population variance.

underestimate

A researcher is interested in whether a new teaching method influences the public speaking skills of students in an introductory to communications class. The researcher knows that public speaking skills in the class are normally distributed with μ = 10 and σ = 2. Which is the null hypothesis for this research study?

μ = 10

I researcher collects a sample of n = 20 introductory psychology textbooks and records a number of pages in each book. The results are than placed in a grouped frequency distribution table using intervals of 0-99 pages, 100-199 pages, 200-299 pages, and so on. If the results were converted into a frequency distribution graph which kind of graph will be appropriate?

A histogram or a polygon

Which statement below accurately describes the relationship between the Alpha level, the size of the critical region, and the risk of a type one error?

As the Alpha level increases, the size of the critical region increases, and the risk of a type one error increases.

Which statement below is consistent with making a type one error?

Concluding that a treatment has an effect when it really has no effect

Which statement below is consistent with making a type two error?

Concluding that a treatment has no effect when it really does

A psychologist is interested in whether observing helpful actions while consuming media causes greater future helping behavior. She designed the research study and which one group of participants watched a pleasant television show depicting people helping others for 20 minutes, whereas a second group of participants watched a pleasant television show for 20 minutes where no helping behavior takes place. After watching the show assigned them, participants in each group are then provide the opportunity to help another student who drops a folder of papers, in the researcher records whether each participant helps other students or not in this research study, the control condition is

The group of participants who watch the pleasant television show for 20 minutes where no helping behavior takes place

Which bit of information below is not obtainable from a z-score?

The population mean

When is a researcher at risk of making a type one error?

Whenever H0 is rejected

Organizing a set of scores in a table or computing an average to summarize a data set is an example of using

descriptive statistics

A psychologist who measures relationship satisfaction among couples by observing nonverbal behavior (for example smiling, mimicking partner actions). In this example, nonverbal behavior is an example of a(n)

operational definition

The participants in a research study self-report their sleep quality levels by choosing the response option that best characterizes their average sleep quality per night from the following response options: 1 = extremely low sleep quality, 2 = very low sleep quality, 3 = low sleep quality, 4 = extremely high sleep quality. Which measurement scale is being used to classify sleep quality?

ordinal

A researcher is curious about the average monthly car insurance bill for high school students in the state of Florida. If this average could be obtained, it would be an example of a

parameter

The students in psychology class seem to think that the midterm exam is very difficult. If they are correct, what is the most likely shape for the distribution of the exam scores?

positively skewed

If I hypothesis test produces a z-score in the critical region, which decision should be made?

reject the null hypothesis

Under which circumstance is the score that is 15 points above the mean an extreme score relatively far from the mean?

when the population standard deviation is much smaller than 15

The number of absences for each student within a psychology class is an example of a ____________ variable.

discrete

A sample of scores has a mean of M = 26, a median of 28, and a mode of 29. What is the most likely shape for the sample distribution?

negatively skewed

A researcher is interested in average first semester change in weight (gain or loss) for students at a local college. Thus, they record the individual change in weight for a small group of 25 freshman from this college during their first semester. Then the researcher calculates the average change in weight during the first semester among is 25 students. The average is an example of a

statistic

When is a researcher at risk of making a type two error?

whenever H0 fails to be rejected

Z-scores are useful with regard to inferential statistics primarily because they offer it all by which to determine whether

A sample is noticeably different from a population

Which of the following statements is true regarding the influence of a small alpha level in the context of a hypothesis testing?

A small alpha level reduces the likelihood of a type one error

A researcher surveys a sample of n = 200 college students and asks each person to identify their favorite movie. Which kind of graph should be used to present these results?

Bar graph

After recording the final grade (A, B, C, D, F) for each individual in a class of n = 26 students, the professor would like to display the grade distribution in a frequency distribution graph. Which kind of graph should be used?

Bar graph

Which statement accurately describes the proportions in the body of a normal distribution?

Body proportions are always greater than or equal to .50

Which of the following statements is correct regarding a biased statistic?

A buy a statistic occurs when the average value of a statistic either underestimates or overestimate the corresponding population parameter.

A researcher conducts a study in which they measure how long participants spend trying to solve an impossible problem-solving task before giving up as a measure of perseverance. In this example, perseverance is an example of a(n)

Construct

Percentile ranks are closely tied to which of the following terms?

Cumulative percentages

Which of the following accurately describes a hypothesis test?

Is the testicle technique that uses the data from a sample to evaluate a hypothesis about a population

And a frequency distribution graph with negative skew, scores of the highest frequencies are _________ of the distribution.

On the right side

The normal distribution is an example of a

Smooth curve showing data from a population

Which of the following is directly communicated within the null hypothesis?

The population mean after treatment

Which statement below is not true regarding standardize distributions?

The values for the mean and standard deviation for a standardized distribution match those values obtained in the original distribution.

In order for a researcher to obtain a random sample, they need to specifically do which of the followingthings?

ensure that each person in the population has an equal chance of being selected for the sample

Because sample variances our computer by dividing SS by n - 1, the average value of the simple variances from all possible random samples consistently ________ the population variance.

equal

Which type(s) of frequency distribution graph(s) should be used for data that come from an interval scale of measurement?

histograms or polygons

Consider that a researcher is attempting to reduce the expected distance between M and μ as much as possible when conducting research study. One thing they can do is

increase the sample size

A recent study reported that students who just finished playing a pro social video game or more likely to help others then students who had just finished playing a neutral or antisocial game. For the study, the kind of game given to the students was the

independent variable

It is only appropriate impossible to calculate the variance and standard deviation as measures a variability for variables measured using a(n) __________ scale of measurement.

interval or ratio

students in an introductory art class are classified as art majors and non-art majors which scale of measurement is being used to classify the students?

nominal

A researcher may decide to transform original scores into a distribution with a predetermined mean and standard deviation other than the z-score distribution because the z-score distribution

often contains decimals and negative values

A biologist records the number and types of fish caught in a local lake during a two-year period. The biologist reports that 7% of the fish caught during this period were trout. Whereas 43% of the fish caught were bass. These reports of the number of trout and bass at this lake are examples of

relative frequencies

In which circumstance as he computational formula preferred over the definitional formula when computing SS, with some of the square deviations, for a population?

when the population mean is not a whole number