15 - DESCRIPTIVE STATISTICS

Question 1

Distribution of a Variable

Answer 1

The way the scores are distributed across the levels of that variable.

(score - distributed - levels of that variable)

Question 2

Frequency Tables

Answer 2

to display the distribution of a variable

The first column lists the values of the variable—the “possible scores” on the Rosenberg scale

and the second column lists the “frequency of each score”

Question 3

Histograms

Answer 3

“graphical display” of a distribution.

It presents the same information as a frequency table but in a way that is even “quicker and easier to grasp”

Question 4

Central Tendency (*)

Answer 4

its middle—the point around which the “scores in the distribution” tend to “cluster”

Question 5

Central Tendency - The mean of a distribution (symbolized M)

Answer 5

is the “sum of the scores” divided by the “number of scores”

Question 6

Central Tendency - The median

Answer 6

expresses that value whose “occurrence lies in the middle” of an ordered set of values

is the “middle score” in the sense that half the scores in the distribution are “less than” it and half are “greater than” it

Question 7

The mode

Answer 7

value in a string of numbers that occurs most often

is the “most frequent” score in a distribution.

Question 8

Measures of Variability

Answer 8

The variability of a distribution is the extent to which the scores vary around their central tendency.

One simple measure of variability is the “range”, which is simply the difference between the highest and lowest scores in the distribution

By far the most common measure of variability is the “standard deviation” - the “average distance between the scores and the mean”

Question 9

two sets of measures
- Measure of central tendency
- Measure of variability

Answer 9

Measure of central tendency - describe the “typical” respondent or response

Measure of variability - describe how similar (dissimilar) respondents or responses are to (from) “typical” respondents or responses