Week 1

Question 1

descriptive statistics

Answer 1

a quantitative summary of information to summarize, organize, and simplify data
- uses center measures (mean, median, mode)
- uses dispersion measures (variance, standard deviation)

Question 2

inferential statistics

Answer 2

techniques that allow to study samples and then make generalizations about the population

Question 3

experimental method

Answer 3

one variable is manipulated while another variable is observed and measured, establishing a cause-and-effect relationship

Question 4

nonexperimental method

Answer 4

“independent variable” is quasi-independent variable because it is not manipulated

Question 5

random variables

Answer 5

variables whose possible outcomes are the result of a random phenomenon
- often written down with ‘X’ or ‘Y’

Question 6

discrete (quantitative) variables

Answer 6

the possible outcomes for the variables that can be captured in a finite, countable list of values

Question 7

continuous (qualitative) variables

Answer 7

the possible outcomes of the variables that can take on any value within a certain interval

Question 8

real limits

Answer 8

boundaries of intervals for scores that are represented on a continuous number line
- exactly located halfway between scores upper and lower real limit

Question 9

four measurement levels

Answer 9

• nominal scale: set of categories that have different names, no quantitative distinctions between observations, and no zero
• ordinal scale: set of categories that are organized in an ordered sequence (ranked), and named, with no equal distance between ranks and no zero
• interval scale: intervals are the same size, and a zero point does not mean a zero amount
• ration scale: intervals are the same size and have an absolute zero point

Question 10

frequency distribution

Answer 10

organized tabulation of number of individuals located in each category on the scale of measurement

Question 11

probability distributions

Answer 11

show the probability of each possible outcome for a random variable

Question 12

skewed distribution

Answer 12

scores pile up toward one end and taper off gradually at the other end
- tail of distribution: section where it tapers off
- positively skewed: tail on right side
- negatively skewed: tail on left side

Question 13

interpolation

Answer 13

• a single interval is measured on 2 separate scales, the endpoints are known for each scale
• you have an intermediate value on one of the scales

Question 14

interpolation calculation

Answer 14

• find width of interval on both scales
• locate position of value - distance to top/width of interval = fraction
• distance = fraction * width of interval
• use distance to determine position