Flashcards in Measurement Deck (32)

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1

## What are the ordinary concerns of measurement in business?

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- Ensuring the units/individuals work on their Key Result Areas (KRA), where performance is measured using Key Performance Indicators (KPI)

- Securing that members possess and develop behaviours and competencies, or knowledge, skills, abilities and other characteristics (KSAOs)

2

## What is measurement?

### Measurement in the process of assigning numbers to objects in such a way that specific properties of objects are faithfully represented by the properties of numbers

3

## What is operationalisation?

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- The process of defining concepts into measurable factors

- The definition of a concept will affect the way we measure it

4

## What are the different types of scales?

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* Nominal Scale

* Ordinal Scale

* Interval

* Ratio

5

## What are nominal scales?

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- Categorical with no inherent order

- Assigns a value to an object for identification or classification purposes only

- Arbitrary scaling - each value can be assigned to any of the categories - size of the number tells nothing about the objects being measured

- Analysis involved counting and determining modal distribution

6

## What are ordinal scales?

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- Categorical with an inherent order/ranking

- Allows things to be arranged in order based on how much of some concept they possess

- Does not tell how close or far apart the objects are from each other

- Analysis can involve counting, measures of central tendency (mode, median and range)

7

## What are interval scales?

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- Indicates difference in values between points with no 0 point, therefore cannot say anything is double anything else etc

- Have both nominal and ordinal properties, but they also capture information about differcens in quantities of a concept

- Unit of measurement is arbitrary - scale does not exactly represent some phenomenon. Zero does not mean absence of the characteristic

- Temperature in F - 40 isn’t ‘double’ as hot as 20

8

## What are ratio scales?

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- Interval with an absolute zero

- Has all the properties of interval scale with an additional attribute of representing absolute quantities. Zero represents an absence of a concept

- Represent absolute meaning

- Analysed through counting, central tendency, variance and dispersion

9

## What types of measures are there?

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* Discrete measures

* Continuous measures

* Index measures

* Composite measures

10

## What are discrete measures?

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- Those that only take one of a finite number of values

- Most often used to represent a classification variable

- Nominal or ordinal measures

- Only statistical measure possible is the mode

- e.g. marital status, gender, ethnicity

11

## What are continuous measures?

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- those that reflect the intensity of a concept by assigning values that can take on any value along some scale range

- Mean and dispersion can be measured

- i.e ratio measures

- e.g. income, age

12

## What are index measures?

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- An index assigns a value based on how much of the concept being measured is associated with an observation

- Often are formed by putting several variables together

13

## What are composite measures?

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- Assign a value to an observation based on a mathematical derivation of multiple variables

- Summated scales

14

## What are summated scales?

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- Composite measures

- Reverse coding - deducting a variables instead of summing it where appropriate

15

## What are the measures of the quality of measures?

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* Reliability

* Validity

* Sensitivity

16

## When is a measure reliable?

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- A measure is reliable when it is accurate and different attempts at measuring something converge on the same result

- Scores vary because of variability in true scores or variability due to measurement errors

- If errors are responsible for much of the variability in the observed variance in test scores, they will be unreliable

17

## What are sources of systematic error?

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* Test characteristics and assessment conditions

* Perceptual errors

* Deliberate distortion & demand characteristics

* Characteristics of the test taker

18

## What test characteristics and assessment conditions might cause systematic error?

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- Poor test items

- Poor comprehension of test instructions

- Freedom from distractions

- Adherence to time limits

19

## What is the goal in estimating reliability in measures?

### Goal is to determine how much of the variability in test scores is due to errors in measurement

20

## How can measure reliability be estimated?

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* Alternate Forms

* Test-retest

* Internal consistency tools

21

## How are alternative forms used to establish the reliability of a measure?

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- More than one form of a test to measure the same concept is run

- Forms are administered to different groups to determine reliability coefficient, the extent to which the scores across the forms correlate

- Alternate test forms are difficult to develop and expensive to administer

- Difficult to establish that the measures are parallel

22

## How is test-retest used to establish the reliability of a measure?

### A questionnaire is used in a pilot test, then later, the same test is repeated and compared for consistency; administering the same scale or measure to the same respondents at two separate points in time to test for stability

23

## What are the problems with using test-retest to establish reliability of a measure?

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- Sensitised respondents

- Attitude change or maturation of subjects

- Time consuming

- Costly

24

## How are internal consistency tools used to establish the reliability of a measure?

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- Looks at the inter-correlations among items

- Internal consistency represents a measure’s homogeneity

25

## What are the two steps to internal consistency tools in measuring reliability of a measure?

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- Split half method

- Method of assessing internal consistency by checking the results of one half of a set of scaled items against the results from the other half: used to test equivalence reliability

- Coefficient alpha

- Compute the average of all possible split half reliability for a multiple item scale where the coefficient demonstrates whether or not the different items converge

- Represents the average of all possible split-half reliabilities for a construct

- 0.85-0.95 is very good reliability

26

## How is validity related to measures?

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- Of measurement

- The extent to which a measure represents the intended concept

- Of decisions

- The extent to which a measure can predict outcomes

27

## What forms of validity are there in regard to measures?

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* Face

* Content

* Criterion

* Construct

28

## How does face validity relate to the quality of a measure?

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- A scale’s content logically reflects what was intended to be measured

- Relies on census among experts that test items match definition

- On the surface the scale or test measures what it is supposed to measure

29

## How does content validity relate to the quality of a measure?

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- Ensures that the scale includes an adequate and represenative set of items that tap a concept

- The degree that a measure covers the breadth/domain of the concept

- Refers to how representative the measures are of the construct domain

30