Research final spring 22

An individual at the 50 percentile would have a z-score of

0

Which one of these correlation coefficients has the least predictive value?

0.19

What is the correlation coefficient of Group X and Group Y. Use the Excel file

0.710116

Using the file 'Excel File for Midterm 2022,' determine the correlation Coefficient between Group B and Group C? Give answer to at least 3 decimals and indicate whether it is a relatively strong or relatively weak correlation.

0.803869861, strong

Using the z-tables on Moodle, what percentage of the population has a Z-score less than -2.20? (give answer to 2 decimals)

1.39%

Your sample consists of 15, 14, 21, 19, 28, 17, 19, 23, 14, 26, 21. What is the range of your sample?

14

For a sample of 3, 4, 3, 5, 1, 6, 3, 4, 6, 7, 9. What would be the mode?

3

What is the Median and Standard Deviation of Group S? Use Excel File

360, 25.22977

What is the Mean and Standard Deviation of Group T? Use the Excel file

367.0435, 40.36366

For a sample of 3, 6, 2, 4, 8, 3, 5, 1, 6, 3, 4, 8, 6, 2, 7, 9, 6. What would be the median?

5

A student is passing their professor in the hall and wants to know how they did on their recent exam. The professor is in a hurry and can only tell them that their score was at the median of the class. What percentile would this represent?

50 percentile

Which of the following sets of scores has the largest standard deviation?

6, 11, 38, 55, 68

What percentage below is a close approximation of the population in a normal distribution that would fall within one standard deviation above and one standard deviation below the mean?

68%

A research hypothesis states that an intervention with a specific therapy will have a clinically beneficial effect. What kind of hypothesis is this?

A directional hypothesis

Which of the following is NOT an example of a possible location threat?

All tests are given in a noisy gymnasium.

Sarah Wilson recruited 100 youths from a church by convenience sampling, and then introduced a 12-month discipleship program to them. Using an instrument to 'measure' spirituality, she pre-tested them at the beginning, then repeated the measurement every two months, and finished with a post- discipleship measurement. Assume that the spirituality instrument is good (reliable and valid), what is/are the possible threat(s) against internal validity of this study?

Mortality, Selection of subjects, Testing, All of the above

The number on the jersey of each soccer player

Nominal

Types of colors in a M&M candy sack.

Nominal

religious affiliation

Nominal

The order that marathon runners finish a race

Ordinal

The best sampling strategy one might use to facilitate obtaining representative results if the study includes numerous intact subgroups is

Random cluster sampling.

The number of college credits earned

Ratio

range of motion at elbow measured in degrees

Ratio

subjects height in inches

Ratio

Which of the following best fits the description of a weak positive correlation?

Red chart, large scatter plot / up and to the right

Which of the following would best fit the description of "having a strong positive correlation?

Red, scatter plot close together / up and to the right

Below are 12 students that are available to participate in your study. You need to choose 3 using simple randomized sampling technique. Random numbers are provided after the list of names. Without renumbering the students, which student would be the second to be selected? 1. Sam 2. Bill 3. Sally 4. Tom 5. William 6. Sarah 7. Veronica 8. Molly 9. Frank 10. Craig 11. Phillip 12. Juan Random Numbers 30, 01, 42, 28, 27, 23, 22, 24, 06, 11, 08, 03, 44, 20, 11, 14, 34, 35, 09, 11, 04, 40, 14, 30, 02, 26, 01, 40, 49, 10

Sarah

A test was given to two different sections of a course. The results were as follows: Section I which meets at 9:00 AM Mean: 51; Standard deviation: 7 Section II which meets at 1:00 PM Mean: 51; Standard deviation: 13 Which of the following conclusions can be inferred correctly?

Section I has less variability (more homogeneous) than Section II.

Which of the following might be a possible testing threat to the internal validity of a study?

Students are tested before and after an intervention.

The Heart Healthy program is a one-day seminar targeted at education surrounding healthy food choices and cooking skills to reduce risk of major cardiac events. A pretest is given to see how knowledgeable participants are regarding heart healthy foods and how best to prepare them. The day after the seminar a post-test is circulated to discern program impact. Which of the following would pose the greatest threat to internal validity?

Testing

For the following two groups perform a T-test (two sample assuming equal variance). Group 1: 3,4,5,6,3,4,5,6 Group 2: 4,5,6,6,4,5,6,6 Which of the following is the t-statistic? (t statistic will be either positive or negative depending on order that you input data but meaning is the same)

(+/-) 1.4255

Prior to the availability of human growth hormone generated by new biotechnology, the only source was purification from cadaver pituitaries. This meant a very limited supply and very strict restrictions on who qualified for treatment. Assume that the restriction was that only children measuring in the bottom 5 percent of the height charts qualified for treatment. Using the z-tables on Moodle, what z-score would children have to be at or below to qualify for growth hormone treatment?

-1.65

A test is given and results in a mean of 50 with a standard deviation of 5. One student has a score of 40 and want to know what their z-score is. You can tell them it is

-2.0

A non-parametric test should be used if:

The level of measurement is nominal scale

The threat of "subject characteristics" refers to differences among subjects that would act as:

an extraneous variable.

Construct validation primarily involves:

assessing evidence on predictions made from theory.

Which of the following is an example of a categorical variable?

eye color

The accessible population in a study is the:

group from which one selects a sample.

A regression threat to internal validity refers to the fact that:

groups selected at extremes will score closer to the average on retesting.

Loss of subjects is a threat to internal validity because:

those lost may differ on the dependent variable from the remainder.

A categorical variable is one that varies in:

type but not amount

A history threat to internal validity refers to the possibility that:

unknown events occurring during the study may affect the dependent variable.

An implementation threat to internal validity in a study comparing two methods is best controlled by:

using many teachers with both methods.

Which of the following correlation coefficients demonstrates the maximum possible correspondence or correlation between two variables?

−1.00

Which of the following is NOT a means of determining reliability by assessing internal consistency?

the test-retest method

A researcher wants to determine the effect an intervention on grade school autistic children in the Indiana. They have been given permission to work with autistic children in the Fort Wayne School district. For this proposal what group is considered the Target Population.

Autistic children grade school age in the Indiana

Which of the following is a nondirectional hypothesis?

Boys and girls will differ in their attitudes toward school.

A study reports data for two groups that is categorical and makes no assumptions of the population from which the sample is drawn. The nonparametric test for differences in the frequency of counts between the categories in within the two groups in situations like this is:

Chi square (X2).

Which of the following is considered more objective than the others?

Criterion-related evidence of validity

In a study looking at two variables of gender and the ability to perform a balance exercise routine. In this study the ability to perform a balance routine would be what type of variable?

Dependent variable

When researchers develop two similar versions of the test based on the same content and criteria, the researcher is using what technique to establish reliability?

Equivalent/Parallel forms

In which of the following is a history threat least likely to occur?

Experimental and control groups are from the same classes in school.

A strong correlation between two variables implies causation.

False

If your research hypothesis is directional and you are using a t-test to determine if there is a significant difference between means, you should a two-tailed test.

False

The results of causal-comparative studies are relatively easy in interpretation since they prove cause and effect.

False

The equivalent-forms method to the same group of subjects at the same time would be a type of

Instrument reliability

value between units is equal but scale lacks a true zero

Interval

Sam Random Numbers Bill 63, 19, 68, 65, 12, 67, 98, 09, 37, 54, 79, 88, 07, 23, 02, 50, 08 Sally Tom William Sarah Veronica Molly Frank Craig Phillip Juan Above are 12 students that are available to participate in your study. You need to choose 3 using simple randomized sampling technique. Random numbers are provided to the left of the list of names. Without renumbering the students, which student would be the first to be selected?

Juan

A test is given to 200 hundred students. Many of the students did very well and in fact the most common score on the exam was 80%. With just this information which of the following had been identified?

Mode

A study is started in which has 12 volunteer participants in the intervention group and 12 volunteers in the comparison group. With time, half of the participants in the intervention group feel the study is taking more time than they want to give and quit the study. What type of threat would this be to internal validity?

Mortality

Which of the following findings is most likely to be concerned with a maturation threat?

Third-grade reading scores demonstrated substantial gains after 12 months of perceptual training.

A research project had been evaluated and deemed 'lacking internal validity.' This should cause concern about the value of any results the project may generate.

True

Assuming random selection of the sample, the larger the sample size the better estimate the sample mean is of the population mean.

True

Instruments that use direct observation are highly vulnerable to observer differences in scoring.

True

When investigating a potential instrument to use in your research project the most important first consideration of those listed below is:

Validity

Generalizing research findings from a sample to the population is most likely to be justifiable when:

a large random sample is used.

You are asked to generate a sample of 10 from a list of 100 patients. This patient list is composed of 60% men and 40% women. In using the technique of simple random sampling how many men will end up in you sample of 10?

cannot predict how many men in sample of 10

Criterion-related evidence of validity would be provided by:

comparing scores on an instrument with scores on another instrument given to measure the same variable.

Which of the following is the best synonym for reliability?

consistency

Which of the following would be the least appropriate variable to assess with an observational tally sheet?

critical thinking

Content-related evidence of validity would be provided by:

having experts review the test.

Statements or predictions of the possible outcomes of a study are called:

hypotheses

If a researcher studies the effects of frustration on the frequency of aggressive behavior, the degree of frustration should be regarded as a(n):

independent variable.

Identify the least-effective means of controlling data collector bias.

informing data collectors of the method group they will be testing

Do a linear regression analysis on Group D Pre-test and Post-test data in the file 'Excel File for Midterm 2022.' Use the Post data as the x variable and the Pre data as the y variable. What is the intercept and what is the slope of the best fit line that the analysis generated? (intercept = , slope = ) Give answer to at least 3 decimals

intercept = 50.976, slope = 0.1821

The most important aspect in selecting a sample is that:

it must try to be representative of the population.

A good defense for maturation as a threat to internal validity is:

large appropriate control group

An extreme outlier will have the greatest effect on which of the following?

mean

What two values are needed to determine the coefficient of variation?

mean & standard deviation

Objectivity in research means:

minimizing personal bias

Using the file 'Excel File for Midterm 2022', do an Analysis of Variance (Single Factor) on Groups A, B and C. Are the Differences between the means of these three groups considered significant at the 95% confidence level? What is the p value?

no, 0.080812945

The mean of the population is defined as an:

parameter

A class of yoga is started among a retirement population to encourage physical activity, as well as mental well-being. After six months, the instructor picks two individuals that have been with the program the longest and selects them fill out a survey on the benefits of the course. What type of sampling would this be?

purposive sampling

Data collected on the yearly income of subjects would be

ratio

On investigator is convinced that his new teaching method will be the most beneficial to those that struggle in school. He is allowed to use 2 third grade classes for his project. He screens all of the student and only uses those that perform poorly. Although he is quite optimistic about his project, this investigator should be concerned for what type of threat to internal validity?

regression

The dependent variable is so called because:

scores on this variable are hypothesized to depend on, and vary with, the value of the independent variable.

Two-stage random sampling refers to:

selecting groups and then individuals.

You are given the mean of a sample. What one other bit of information would you need to determine the 95% confidence interval of that mean?

standard error of the mean

The major threat to internal validity in a causal-comparative study is the possibility of a:

subject characteristics threat.

Using a personality inventory is an example of

subject supplied data

Subjects performing well merely because they are being observed (and not necessarily because of any effect of treatment) are considered to be under the influence of:

the Hawthorne effect.

Instrument decay refers to the possibility that:

the effectiveness of the instrument is altered during the course of a study.

"Students taught first aid by programmed instruction will achieve at a higher level than those taught first aid by the traditional method." The independent variable in this hypothesis is:

the method of instruction.

In using a table of random numbers, _____.

the number of digits used is determined by the population size