Scale of measurement

Levels of measurements
nominal scale
ordinal scale
interval scale
ratio scale

1. Chi-square Presented by Dr. Hina Jalal hinansari23@ @ gmail.com SCALE OF MEASUREMENT 2 Educat i onal Statist i cs

2. Scale of measurement Scales of measurement is  how variables are defined and categorised . Psychologist Stanley Stevens developed the four common scales of measurement. Each scale of measurement has properties that determine how to properly analyse the data. There are four types of measurement scales: nominal, ordinal, interval, and ratio .

3. Scale of measurement The  Scales of Measurement  are used to  quantify or categorize  the variables and before any research one must identify the type of the variable under study. As different methods are used to measure different variables

4. The scale of measurement of variables determines the mathematical operations of variables. These mathematical operations, determine which statistics can be applied to the data. Interval Data: Temperature, Dates (data with an arbitrary zero Ratio Data: Height, Weight, Age, Length (data that has an absolute zero) Nominal Data: Male, Female, Race, Political Party (categorical data that cannot be ranked) Ordinal Data: Degree of Satisfaction at Restaurant (data that can be ranked). Scale of measurement

5. Measurement Scales T 

6. Nominal Scales Nominal scales are naming scales that represent categories where there is no basis for ordering the categories. Nominal Scale Examples diagnostic categories gender of the participants classification based on discrete characteristics (hair color) group affiliation (Republican, Democrat)

7. Nominal Scales Examples the town people live in a person's name an arbitrary identification, including identification numbers that are arbitrary menu items selected any yes/no distinctions most forms of classification (species of animals or type of tree) location of damage in the brain

8. Ordinal Scales In ordinal scales, numbers represent rank order and indicate the order of quality or quantity, but they do not provide an amount of quantity or degree of quality.

9. Ordinal Scales Examples World cup teams any rank ordering class ranks social class categories order of finish in a race Boards result positions Race competitions

10. Interval Scales In interval scales, numbers form a  continuum  and provide information about the amount of difference, but the scale lacks a true zero. The differences between  adjacent  numbers are equal or known. If zero is used, it simply serves as a reference point on the scale but does not indicate the complete absence of the characteristic being measured. The  Fahrenheit  and  Celsius   temperature  scales are examples of interval measurement. In those scales, 0 °F and 0 °C do not indicate an absence of temperature

11. Interval Scales Examples Scores on scales that are standardized with an arbitrary mean. Scores on scales that are known to not have a true zero (e.g., most temperature scales except for the Kelvin Scale) Scores on measures where it is not clear that zero means none of trait (math test) Scores on most personality scales based on counting the number of endorsed items

12. Ratio Scales Ratio scales are the easiest to understand because they are numbers as we usually think of them. The distance between adjacent numbers is equal on a ratio scale and the score of zero on the ratio scale means that there is none of whatever is being measured. Most ratio scales are counts of things.

13. Ratio Scales Examples Time to complete a task Number of responses given in a specified time period Weight, length, height of an object Number of children in a family Number of accidents detected Number of errors made in a specified time period

14. Importance of Scales The most important reason for making the distinction between these measurement scales of is that it affects the statistical procedures used in describing and analyzing your data. There are dozens of examples of measures at each of these levels of measurement, along with some exercises help in understanding of these distinctions.

15. Dr. Hina Jalal @AksEAina ([email protected])