Chapter 2-norms & basic stats

Question 1

Measurement def

Answer 1

Process of obtaining a NUMERICAL description of the degree to which an individual possesses a particular characteristic
-> Assigning numbers to obj

Question 2

Outcome of measurement

Answer 2

Assign an individual/obj to a category (number)

Question 3

A measurement scale determines the kinds of: (2)

Answer 3

(1) STATISTICAL procedures that can be applied to the scores produced by the measure
(2) COMPARISONS we can make among individuals using that scale

Question 4

Nominal scale def

Answer 4

Numbers are assigned to represent labels or categories of data only

Question 5

Appropriate Statistics for Nominal scale (2)

Answer 5

Frequency, mode

Question 6

Ordinal scale def

Answer 6

Numbers are assigned to rank-ordered data. The distances between numbers are NOT equal

Question 7

Appropriate stats for Ordinal scale (5)

Answer 7

Frequency, mode, median, percentile, rank-order correlation

Question 8

Interval scale def

Answer 8

(1) Numbers are assigned to rank-ordered data, and (2) the DISTANCE between numbers is EQUAL. There is NO absolute zero point (i.e., a number indicating the complete absence of what is measured).

Question 9

Appropriate stats for Interval scale (6)

Answer 9

Frequency, mean, mode, median, percentile, Pearson correlation, t test

Question 10

Ratio scale def

Answer 10

(1) Numbers are assigned to rank- ordered data, (2) the distance between numbers is EQUAL, and (3) there IS an absolute zero point.

Question 11

Appropriate stats for Ratio scale (7)

Answer 11

Frequency, mean, mode, median, percentile, Pearson correlation, proportion, t test

Question 12

Norm def

Answer 12

Test scores achieved by a defined group of individuals (i.e., norm sample).

Question 13

Norm-based interpretation

Answer 13

Compare an individual’s score to the norm group

Question 14

Types of Norms (3)

Answer 14

(1) DEVELOPMENTAL Norms
(2) WITHIN-GROUP Norms
Norms without a Norm Sample
(3) CRITERION-REFERENCED Norms

Question 15

Developmental Norms def

Answer 15

Typical level of performance in each of the AGE group or grade levels that the test’s target population comprises.
-> Age-equivalent or grade-equivalent scores are assigned based on the MEDIAN RAW SCORE for that chronological age or grade level.
-> Median = TYPICAL score = norm

Question 16

Within-Group Norms (3)

Answer 16

(1) Percentiles
(2) Z-scores
(3) Transformed standard scores

Question 17

Percentiles def

Answer 17

Percentage of individuals falling below a test score

Question 18

Standard Deviation def

Answer 18

A measure of the average distance of scores from the mean.

Question 19

Transformed Standard Score formula

Answer 19

Bz + A
B = desired SD
A = desired Mean

Question 20

Percentiles advantages (3)

Answer 20

(1) Easy to grasp
(2) Easy to compute
(3) Interpretation doesn’t change with the shape of the distribution

Question 21

Percentiles disadvantages (2)

Answer 21

(1) Magnifies differences near mean; minimizes differences at extremes
(2) Some common statistical analyses are NOT possible with percentiles

Question 22

Standard scores advantages (2)

Answer 22

(1) Gives a sense of distance from the mean
(2) Can be used in most common statistical analyses

Question 23

Standard score disadvantages (2)

Answer 23

(1) Unfamiliar to many non-specialists
(2) Interpretation difficult when distribution not normal

Question 24

Criterion-Referenced Norms def

Answer 24

Evaluate performance relative to an absolute criterion or standard rather than performance of other individuals.
-> An absolute vs relative evaluation

Question 24

Within-Group Norms: Criticisms (2)

Answer 24

(1) Only meaningful if the standardization (norm) sample is representative
(2) Within-group comparisons encourage competition

Question 25

Requirement for Criterion-Referenced Norms

Answer 25

Define content of domain narrowly and specifically.
E.g. Driving skills, 8th grade math curriculum

Question 26

Criterion-Referenced Norms: Issues (3)

Answer 26

(1) Can elements of performance be specifically defined?
-> Hard to clearly define what “good” or “bad” performance looks like.
-> Criterion-referenced norms require a clear standard (e.g., scoring 80% on a test to pass), but creating these standards can be challenging because it’s hard to decide what knowledge or skills are essential.
(2) Focus on minimum standards
-> e.g., “Did you pass?”
-> Ignore how much better one person is compared to others.
(3) Absence of relative knowledge
-> You don’t know how someone performs compared to others.

Question 27

Developmental norms cons

Answer 27

Often interpreted inappropriately
-> Overgeneralization, misinterpreting median…

Question 28

Developmental & within-groups norms are dependent on _______________

Answer 28

the quality of norm sample

Question 29

Criterion-referenced norms have limited ___________

Answer 29

applicability

Question 30

Norm-referenced testing convert raw score to ___________ score

Answer 30

standardized

Question 31

What is an elevated score?

Answer 31

2 z-scores

Question 32

Characteristics of a GOOD norm sample (3)

Answer 32

(1) Sufficiently LARGE (avoid sampling error)
(2) Representative of the largest population
(3) Contemporary

Question 33

Properties of scales (3)

Answer 33

(1) Magnitude
(2) Equal Intervals
(3) Absolute 0

Question 34

Propriety of Magnitude def

Answer 34

A scale has the property of magnitude if we can say that a particular instance of the attribute represents more, less, or equal amounts of the given quantity than does another instance.

Question 35

Propriety of Equal Intervals def

Answer 35

A scale has the property of equal intervals if the difference between two points at any place on the scale has the same meaning as the difference between two other points that differ by the same number of scale units.

Question 36

Propriety of Absolute 0

Answer 36

An absolute 0 is obtained when nothing of the property being measured exists.

Question 37

Frequency distribution def

Answer 37

Displays scores on a variable/measure to reflect how frequently each value was obtained.

Question 38

The greater the percentile, the more ______________

Answer 38

la personne est bonne!!!

Question 39

McCall’s T

Answer 39

Same as standard scores (Z scores), except that the M=50 and SD=10.

Question 40

Standardization vs normalization

Answer 40

McCall’s T, z-scores (…) - Do not change the characteristics of the distributions.
If a distribution of scores is skewed before the transformation is applied, it will also be skewed after the transformation has been used.

Question 41

Transformations _________ but do not _______.

Answer 41

standardize; normalize

Question 42

Interquartile range

Answer 42

Interval of scores bounded by the 25th and 75th percentiles.
-> bounded by the range of scores that represents the middle 50% of the distribution.

Question 43

Deciles

Answer 43

Use points that mark 10%.
-> Thus, the top decile, or D9, is the point below which 90% of the cases fall. The next decile (D8) marks the 80th percentile, and so forth.

Question 44

Stanine system

Answer 44

Converts any set of scores into a transformed scale, which ranges from 1 to 9.
M = 5, SD = 2

Question 45

Overselection

Answer 45

Selecting a higher percentage from a particular group than would be expected on the basis of the representation of that group in the applicant pool.

Question 46

Overselection is a problem with ______

Answer 46

Within-Group Norms

Question 47

Tracking (developmental norms)

Answer 47

Tendency to stay at about the same level relative to one’s peers.

Question 48

Big Data

Answer 48

Revolution in social science research.
= Data sets with sizes beyond the ability of commonly used software tools to capture, curate, manage, and process the data within a tolerable elapsed time.