Representation, Norms, and Validity
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AP Psychology › Representation, Norms, and Validity
Which of the following measures is reliable but not valid?
A scale that shows you that you are 50 pounds every time you step on it, but you know that you are really 150 pounds
A scale that shows a different weight between 50-150 pounds every time you step on it
A scale that shows you between 140-160 pounds every time you step on it and you know you weigh 150 pound
A scale that tells you that you weigh 200 pounds when you know you weigh 150
A scale that does not tell you a weight
Explanation
A study is valid if it measures what it is supposed to measure and reliable if it produces similar results every time. The choice that stated “a scale that shows you that you are 50 pounds every time you step on it (i.e. reliable), but you know that you are really 150 pounds (i.e. not valid)” is reliable but not valid.
Which of the following is an appropriate definition for "measure of variation?"
The measure of how scattered a numerical data set is
The measure of deviation from the norm
The total sum of deviations from the norm
The sum of the highest and lowest numbers in the data set
None of these
Explanation
In a numerical data sheet, numbers can vary greatly. The measure of how much variation (or dispersion) there is is called the measure of variation.
Stacy would like to test whether an anti-depressant effectively reduces symptoms of depression. She gives depressed participants a questionnaire before administration of the drug. Half of the participants receive the drug for six weeks, and the other half receive a placebo sugar pill. She then gives the same questionnaire to assess any changes in symptoms.
If the participants in Stacy's study are all caucasian males, which of these would most likely be threatened?
External validity
Internal validity
Reliability
Construct validity
Ethics
Explanation
External validity refers to the gerneralizability of your data. If there are only caucasian males in Stacy's study, her findings may not generalize to other groups, such as females or other races.
A well-designed test should have __________.
high reliability and high validity
low reliability and low validity
high reliability and low validity
low reliability and high validity
each choice indicates an equally well-designed test
Explanation
Validity is the term for how well a test measures what it has been designed to measure. Reliability refers to the ability to consistently find similar results when a test is repeatedly administered in similar conditions. High validity and high reliability will ensure that a test accurately determines what it claims to determine, and that its findings are not simply caused by random chance.
The Flynn Effect describes which of the following?
The substantial worldwide increase in intelligence test scores in the past century
The substantial worldwide decrease in intelligence test scores in the past century
The substantial worldwide increase in intelligence test scores of men in the past century
The substantial increase in European and North American intelligence test scores in the past century
The substantial worldwide increase in intelligence test scores of women in the past century
Explanation
While a score of 100 indicates average intelligence on a modern IQ test, people who score 100 on these tests generally score much higher on older intelligence tests. Each generation since the 1930s has had increased scores on older tests, an effect studied by James Flynn.
Which is the correct definition for a "standardized score" for a given individual?
A standardized score is a score reflective of a person's status relative to the average of all scores on the given evaluation
A standardized score is a score reflective of a person's status relative to the mode of all scores on the given evaluation
A standardized score is a score reflective of a person's status relative to the median of all scores on the given evaluation
A standardized score is a score reflective of a demographic's status relative to the median of all scores on the given evaluation
None of these
Explanation
A standardized score reflects a person's status relative to the average of all scores on the given evaluation. That is, the standard score reflects a person's relationship with the mean of all scores. If the average of all scores is 70, and a person scores 90, the person's standardized score is positive 20. If the person scores 20 below the mean, their standardized score would be negative 20.
What is the purpose of randomness during the selection process of participants for a study?
It ensures that each individual in a population has an equal chance to be chosen
It completely eliminates the effects of random variables
It guarantees conclusive results
It ensures equal representation of all groups within a population
Explanation
The purpose of random sampling methods is to ensure that one individual does not have a greater chance of selection than any other. Although random sampling reduces the effects of random variables, like error, they are not completely eliminated. Representation is not guaranteed, but is likely heightened. Although randomness does not ensure conclusive results, it helps to validate any results of a study against one that is not random.
By definition, what percentage of the population has an IQ of less than 100?
Explanation
Intelligence quotient (IQ) is defined as having a median of 100. This means that half of the people who take an IQ test will have below 100 and half will have above 100. The standard deviation of IQ is 15, such that two-thirds of the population fall between 85 and 115.
Which type of validity examines how generalizable a study's findings are?
External
Concurrent
Divergent
Construct
Internal
Explanation
External validity looks at the extent to which a study's findings can be generalized to certain populations. Studies that have large sample sizes and diverse participants have greater external validity.
A test that is designed to predict a person's future success in a given area is __________.
an aptitude test
an achievement test
an IQ test
a standardized test
a career test
Explanation
A test that is designed to predict a person's future success in a given area is an aptitude test. This measure has less so to do with a person's current skill set—though that is certainly relevant—and more to do with their talents, inclinations, and interests. A person's aptitude has to do with where a person has the most potential for growth.