Exam 1
Explain the meaning of the finding that there is a negative correlation between class attendance (number of absences) and achievement in class (as measured by the final examination). Use the concept of r square in your explanation.
A negative correlation between the number of absences and test scores indicate that when one value is small for one variable the score value for the other variable is large. So if class absences are low, test scores are high and vice versa. To further understand the correlation it would be useful to test the r-squared value to measure the total variance in test score that could be explain by class absence.
A research article reports that there is 60% common association (or shared variance) between the scores on two measures. Explain what this means. How did they get the 60%? What was the correlation?
This means that the two measures possess a 60% overlap. This indicates there is carryover somewhere between the two. An example would be squat strength and jump height as force production is a prerequisite for jump height. If squat numbers are high they possess the prerequisite strength needed to jump high, but there are other factors that influence jumping ability. The researchers got 60% by finding the correlation coefficient (r) and then squared it to get the r-squared value of .60. If r-squared= .60, then r= 0.77.
What is the mode(s) for the following set of numbers? (5, 10, 4, 1, 4, 5, 12, 8, 9, 4 ) a) 4 b) 5 c) 5.5 d) 4 and 5
a) 4
When a researcher decides that an appropriate analysis for a research model is to evaluate how several variables might influence two other variables that in turn influence the outcome variable of interest, the appropriate statistical analysis is a) LISREL b) canonical correlation c) multiple regression d) factor analysis
a) LISREL
Which hypothesis is stated in the null form? a) There is no difference between the vocabulary scores of average- and high-ability students b) The math achievement scores from School A are significantly higher than the scores from School B c) The perceptual-motor development of first-grade girls is higher than that of first-grade boys. d) There is a positive relationship between attitude toward school and achievement scores
a) There is no difference between the vocabulary scores of average- and high-ability students
The single score which best represents all the scores in a distribution is the definition of a) central tendency b) standard deviation c) variability d) parametrics
a) central tendency
When we say that research is empirical, we mean that the researcher a) collects data on which to base decisions b) solves the problems through rationalization c) controls all extraneous variables d) finds positive support for the research hypothesis
a) collects data on which to base decisions
A researcher finds a correlation of .70 between popularity ratings and self-concept scores. What percentage of common association can be inferred between the two variables? a) 35% b) 49% c) 60% d) 70%
b) 49%
After a population of 1,000 high school seniors is divided by sex and size of school attended, the random selection of a sample to represent these proportions of the population is called a) systematic sampling b) matched pair sampling c) stratified random sampling d) cluster sampling
c) stratified random sampling
When a researcher states that a result is significant, this means that a) the effect is an especially important one b) the scores are not correlated c) the result is unlikely to be a chance occurrence d) the scores are correlated
c) the result is unlikely to be a chance occurrence
If the researcher fails to reject the null hypothesis when there really is a difference, this is an example of a a) one-tailed test b) two-tailed test c) type I error d) type II error
c) type I error
Compared to applied research, basic research a) is of more immediate value to the practitioner b) is done in the "real world", such as the classroom c) usually offers more control, such as in a laboratory d) questions cannot be easily answered
c) usually offers more control such as in a laboratory
A measure of meaningfulness that expresses the difference between the experimental and control group in standard deviation units is the a) effect size b) r squared c) omega squared d) chi squared
a) effect size
The generalizability of the results pertains to what kind of validity? a) external b) internal c) construct d) logical
a) external
If two measures have a high positive correlation and a person has a low score on one measure, his or her score on the other measure is most likely to be a) low b) high c) the same score d) dependent on whether one variable is the cause of the other
a) low
If two measures have a high positive correlation and a person has a low score on one measure, his or her score on the other measures is most likely to be a) low b) high c) the same score d) dependent on whether one variable is the cause of the other
a) low
A researcher wishes to survey opinions on a proposed increases in fees at her university. She decides to select a sample for telephone interviewing by selecting every 20th name in the student directory. What is this type of sampling called? a) systematic b) random c) stratified d) cluster
a) systematic
When a researcher claims that there is a difference between treatments (i.e., rejects the null hypothesis) when there really is no difference, what type of error is this? a) type I error b) type II error
a) type I error
When an experimenter states that the level of significance is the .05 level, he or she is setting the probability of committing which type of error? a) type I error b) type II error
a) type I error
What is the median score for the following set of numbers? (3, 11, 8, 13, 5, 3, 6) a) 5 b) 6 c) 7 d) 8
b) 6
Four skills tests are tried as predictors of success in a tennis class. Each test correlates with later success as follows: test A, r = .27; test B, r = -.90; test C, r = -.40; test D, r = .65. The test that will most accurately predict success is a) Test A b) Test B c) Test C d) Test D
b) Test B
If studying a cancer drug, which type of error would be worse? a) Type I b) Type II
b) Type II
Another term for the mean is the a) variance b) average c) 50th percentile d) median
b) average
Prediction studies use which of the following as the basic analysis technique? a) ANOVA b) correlation c) factor analysis d) multiple-range comparison
b) correlation
A correlational technique frequently used in the construction of an instrument (such as an attitude inventory) that statistically groups test items that seem to be measuring a particular dimension or trait is called a) Spearman r b) factor analysis c) path analysis d) multiple regression
b) factor analysis
A correlation of .00 between two variables indicates a) a perfect positive relationship b) independence ( no association) between the variables c) a perfect negative relationship d) a relationship of unknown degree
b) independence (no association) between the variables
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? a) criterion b) internal c) content d) external
b) internal
Special language that is regularly used in a particular field but which may not be meaningful to people outside the field is called a) communication b) jargon c) concealment d) confutation
b) jargon
The standard deviation represents the a) error in measurement b) spread of scores about the mean c) single score that best expresses the group's performance d) error in sampling from the population
b) spread of scores about the mean
For a predicted score of 30 and a standard error of estimate of 6, the chances are 95 out of 100 that the true score will be between a) 30 and 36 b) 24 and 36 c) 18 and 42 d) 12 and 48
c) 18 and 42
For a group of normally distributed scores with a mean of 30 and a standard deviation of 6, the middle 68% of the scores will be between a) 30 and 36 b) 18 and 42 c) 24 and 36 d) 12 and 48
c) 24 and 36
A researcher decides to use an alpha of .01 and a power of .80. To determine the needed sample size the researcher must ascertain the expected a) beta b) stem-and-leaf distribution c) effect size d) skewness
c) effect size
The term coined by Kuhn to denote the scientific approach that is used widely in the natural sciences is a) alternative science b) descriptive science c) normal science d) analytical science
c) normal science
The term that describes the position of the hump in the curve of a distribution is a) kurtosis b) the stem c) skewness d) the leaves
c) skewness
Say that we are operating a health club and offer aerobic dance and jogging classes for people who want to lose weight. Our research question is this: Which program is more effective in reducing fat? Which is the dependent variable? a) age of the participants b) number of exercise sessions per week c) skin-fold measured fat d) jogging vs. aerobic classes
c) skin-fold measured fat
Which of the following terms least belongs with the others? a) mode b) mean c) standard deviation d) median
c) standard deviation
If a researcher finds a small difference in average test scores between a large sample (over 700) of experimental participants and a large sample (same size) of control participants, it is very likely that the difference is a) statistically significant and has a high degree of meaningfulness b) not statistically significant but has a higher degree of meaningfulness c) statistically significant but does not have a high degree of meaningfulness d) neither statistically significant nor meaningful
c) statistically significant but does not have a high degree of meaningfulness
A researcher conducts a study on the effectiveness of computer-assisted instruction (CAI) by comparing classes that use this method with classes that do not. The researcher expects CAI classes to show higher gains in achievement. This expectation is a) the dependent variable b) the independent variable c) a paradigm d) a hypothesis
d) a hypothesis
A null hypothesis is a) nearly always the same as the research hypothesis b) a statistical hypothesis that assumes that the participants in two treatment groups were unequal before treatment began c) a statistical hypothesis that assumes there is a difference among the effects of the treatments d) a statistical hypothesis that assumes that there is no difference among the effects of treatments
d) a statistical hypothesis that assumes that there is no difference among the effects of treatments
The only type of research that can manipulate treatments and establish a cause and effect is a) descriptive research b) analytical research c) correlational research d) experimental research
d) experimental research
If there is a correlation of .80 between a test of scholastic aptitude and performance on an achievement test, one can infer that a) 80% of the achievement test variance is caused by scholastic aptitude b) 64% of the achievement test variance is caused by scholastic aptitude c) 40% of the achievement test variance is caused by scholastic aptitude d) no causation can be inferred
d) no causation can be inferred
In multiple regression, one is able to predict a) two or more criteria from two or more predictors b) two or more criteria from one predictor c) one criteria from one predictor d) one criteria from two or more predictors
d) one criteria from two or more predictors
Another term that describes the unscientific method of tenacity is a) intuition b) rationalization c) objectivity d) superstition
d) superstition
