Question

Exercises For Conceptual Understanding nearest .01 gram (the sues of these indicate sensitivity to stres). 1. Indicate the scale of measurement used in the studies described below, and justify your choice. c. A military training officer ranked each of 20 cadets on leadership, with the rank of t indicating the greatest leadenhip. a. A public opinion poll was conducted of random sample of registered voters one week before an election. The respondents were asked whether they intended to vote for (1) the Democratic candidate, (2) the Republican candidate, (3) one of the other d. Ms. Smithson, a nutritionist in an elemes tary school, believes that a good breakfat helps children perform better in school She gives an examination containing 40 qs tions on different subjects to two classes of 30 low-income children, one of which given a nutritious breakfast and the other not before the testing b. A psychologhst studied the physiological ef fects of crowding by housing laboratory rats in conditions that were crowded (10 rats per cage) or uncrowded (2 rats per cage). After two months the adrenal glands of all the animals were removed and weighed to the e.Mr. Bates rated the 30 children in his pre- school class on readiness for kindergates by rating them on a five-point scale, 1 least ready and 5 for most ready f. A college teacher gave an essay exam and then graded the papers by using five letter grades A, B, C, D, Fthat represented equally spaced categories of competence. g. Students were asked whether they (1) fa- vored an increase in the student activities fee to be eligible to attend more events, (2) fa- vored no increase in fee to attend the current number of events, or (3) had no opinion. 2. Discuss the differences in the scales of temper- ature produced by the Celsius versus the Kelvin methods. (The Kelvin method uses-273°C as its zero point. This is the point at which all mo- F lecular movement ceases.)

Answer 1

1.

a.

Scale of measurement used : NOMINAL

Reason : The nominal or categorical statistical scale of measurement is used to measure those variables that can be broken down into groups. Each group has attributes distinctly different from the other.

In this case, there are 4 different groups.

b.

Scale of measurement used : RATIO

Reason : Ratio scale is a type of variable measurement scale which is quantitative in nature. Ratio scale allows any researcher to compare the intervals or differences.

In this case, weight is being measured which is quantitative in nature.

c.

Scale of measurement used : ORDINAL

Reason : The ordinal statistical scale of measurement applies to variables that signify, as the root word suggests, “order” of the different groups. It is possible to rank order the different groups because each group shows attributes that are convincingly superior or greater than the other or vice-versa.

In this case, 20 cadets are being ranked from 1 to 20 on leadership.

d.

Scale of measurement used : NOMINAL

Reason : The nominal or categorical statistical scale of measurement is used to measure those variables that can be broken down into groups. Each group has attributes distinctly different from the other.

In this case, there are 2 distinct groups - one of which given a nutritional breakfast and the other not given a nutritional breakfast.

e.

Scale of measurement used : ORDINAL

Reason : The ordinal statistical scale of measurement applies to variables that signify, as the root word suggests, “order” of the different groups. It is possible to rank order the different groups because each group shows attributes that are convincingly superior or greater than the other or vice-versa.

In this case, children are being rated on a five point scale, 1 for least ready and 5 for most ready.

f.

Scale of measurement used : INTERVAL

Reason : Interval scales are numeric scales in which we know both the order and the exact differences between the values.

In this case, exam is graded using five letter grades A,B,C,D,and F that represent equally spaced categories of competence.

g.

Scale of measurement used : NOMINAL

Reason : The nominal or categorical statistical scale of measurement is used to measure those variables that can be broken down into groups. Each group has attributes distinctly different from the other.

In this case, there are 3 distinct groups (1) favored an increase in the student activities fee to be eligible to attend more events, (2) Favored no increase in the fee to attend the current number of events or (3) had no opinion.

2.

The Celsius scale is interval scales because the location of zero on the scale is arbitrary. For a temperature scale to be a ratio scale, zero must NOT be arbitrary. If zero is defined as the temperature where molecular motion stops (absolute zero), then a ratio scale for temperature can be defined.

The Kelvin temperature scale defines zero (0 K) this way. Twice as hot on the Kelvin scale has meaning since the location of zero is not arbitrary. If it is desired to know how how hot it is if it is twice as hot as 30 °C, change 30 °C to Kelvin [303.15 K], double the numerical value in Kelvin [606.3 K], then change the result to Celsius [333.15 °C].

Hence, if we double the temperature in Kelvin scale it is actually twice as hot but this is not the case for Celsius.

So, Kelvin scale has Ratio scale of measurement and Celsius has Interval scale of measurement.