Statistics Refresher

Question 1

this term refers to the act of assigning numbers or symbols to characteristics of things (people, events, whatever) according to rules

Answer 1

MEASUREMENT

Question 2

this term refers to a set of numbers (or other symbols) whose properties model empirical properties of the objects to which the numbers are assigned

Answer 2

SCALE

Question 2

these type of scale includes variables that can theoretically be divided infinitely

Examples include measurements like height and depression levels, which can take on a wide range of values.

Answer 2

Continuous Scales

Question 2

this term refers to the collective influence of all factors affecting a test score that are not specifically measured by the test itself. It can arise from various sources and may impact the accuracy of the test results

Answer 2

error

Question 3

these type of scales consists of categorical values that cannot be subdivided

Examples include gender categories (e.g., male or female)

Answer 3

Discrete Scales

Question 4

what are the three levels of measurement for variables?

Answer 4

nominal, ordinal, interval/ratio

Question 4

in this level of measurement, it involves classification based on distinguishing characteristics

Categories must be mutually exclusive and exhaustive

Examples include types of fruit (e.g., apples vs. oranges) and DSM-IV diagnoses.

Answer 4

Nominal

Question 5

in this level of measurement, it allows for classification and rank ordering of items

While they indicate relative positioning, they do not specify the magnitude of differences

Example: Olympic medal rankings (gold, silver, bronze)

Answer 5

Ordinal Scales

Question 5

in this level of measurement, scales are similar to interval scales but include a true zero point, allowing for the expression of absolute quantities

Examples: Height and reaction time.

Answer 5

Ratio

Question 6

this term refers to a straightforward, unmodified accounting of performance that is usually numerical

Answer 6

RAW SCORE

Question 6

This level of measurement has equal intervals between values, meaning each unit is the same distance apart.

NO TRUE ZERO POINT

Example: temperature (Fahrenheit), temperature (Celsius), pH, SAT score (200-800), credit score (300-850)

Answer 6

Interval

Question 7

this term refers to a set of test scores arrayed for recording or study.

Answer 7

Distribution

Question 8

this term refers to a description of data wherein all scores are listed alongside the number of times each score occurred

Answer 8

frequency distribution

Question 8

this term refers to the straightforward, unmodified accounting of performance that is usually numerical.

Answer 8

Raw Score

Question 9

this measure of central tendency is calculated by summing all observations (or test scores) and dividing by the total number of observations.

Represents the arithmetic average of the data set

Answer 9

Arithmetic Mean

Question 10

what type of skew indicates that a small number of scores are at the high end of the distribution.

skewed to the right

Answer 10

positive skew

Question 10

this measure of central tendency refers to the middle score when all scores in a distribution are arranged in ascending or descending order

Particularly useful for datasets with outliers or extreme scores, as it is less affected by skewed data

Answer 10

median

Question 10

this term describes the asymmetry of a
distribution

Answer 10

skewness

Question 10

this measure of central tendency is the most frequently occurring score in a distribution

If two scores have the highest frequency, the distribution is referred to as?

Answer 10

mode

bimodal

Question 10

this term refers to a statistical measure that identifies the average or central point of a data set, reflecting the midmost score in a distribution.

It provides insight into the typical performance or characteristics of a group.

Answer 10

central tendency

Question 10

what does it mean if a distribution is mesokurtic?

Answer 10

the distribution has a moderate peak, typical of a normal distribution

Question 10

what type of skew indicates that a large number of scores are at the high end of the distribution.

skewed to the left

Answer 10

negative skew

Question 11

this term refers to the “peakedness” of a
distribution

Answer 11

Kurtosis

Question 11

this measure of variability refers to the difference between the highest and lowest scores in a distribution

Answer 11

RANGE

Question 11

this term refers to statistics that describe the extent of variation or dispersion within a distribution of scores

Answer 11

measures of variability

Question 11

what does it mean if a distribution is platykurtic?

Answer 11

the distribution is relatively flat

Question 11

what does it mean if a distribution is leptokurtic?

Answer 11

the distribution is relatively peaked

Question 11

this term refers to the arithmetic mean of the squared differences between each score and the mean. It quantifies the degree of spread in the data.

Answer 11

Variance

Question 12

this measure of variability refers to the difference between the third quartile (Q3) and the first quartile (Q1) of a distribution It measures the range of the middle 50% of scores.

Answer 12

interquartile range (IQR)

Question 13

this type of standard score is a measure that indicates how many standard deviations a raw score is above or below the mean of its distribution.

Answer 13

Z-score

Question 14

this term refers to the raw score that has been transformed to fit a different scale, which has a predetermined mean and standard deviation.

Answer 14

Standard Score

Question 15

this type of standard score is a standardized score where the mean is set at 50 and the standard deviation is set at 10.

Answer 15

T-score

Question 16

what is the difference between t-score and z-score?

Answer 16

Z-scores are used when dealing with larger sample sizes (n > 30) and known population standard deviation, while t-scores are used for smaller sample sizes (n < 30) and unknown population standard deviation

Question 16

this term refers to something that quantifies the strength and direction of the relationship between two variables

Answer 16

coefficient of correlation (or correlation coefficient)

Question 17

what does a positive correlation mean?

Answer 17

Both variables move in the same direction (increase or decrease together).

Question 18

what does a negative correlation mean?

Answer 18

One variable increases while the other decreases

Question 19

this term refers to something that quantifies the strength of the relationship between variables.

Answer 19

effect size

Question 19

this calculation method is used for continuous and linearly related variables. Indicates the degree of linear correlation between two variables. Once calculated, the correlation coefficient should be tested for statistical significance (commonly at a p-value < .05)

Answer 19

Pearson r

Question 20

this term refers to a statistical technique that enables researchers to combine and analyze data from multiple studies to assess the relationship between variables.

Answer 20

Meta-Analysis

Question 20

this term refers to a simple graphing of the coordinate points for values of the X-variable (placed along the graph’s horizontal axis) and the Y-variable

Answer 20

SCATTERPLOT

Question 21

this calculation method is used primarily for ordinal data or small sample sizes A non-parametric measure that assesses how well the relationship between two variables can be described using a monotonic function. uses ranks instead of raw scores, which makes it ideal for ordinal data

Answer 21

Spearman Rho

Question 22

what is the symbol for standard deviation?

Answer 22

σ

Question 23

what are the 5 types of standard scores?

Answer 23

1. Percentile 2. Z-scores 3. Stanine 4. Sten 5. T-scores