Understanding Statistics As A Language. Robert Andrews

      The Matrix view of the Decision Model provides another quick reference in determining the appropriate procedure. (See Table 2) The variables are in the left column; the procedures of choice according to the measurement scale are in the other three columns.

      Table 2: Matrix View of the Decision Model

Groups/Measures	Nominal	Ordinal	Interval/Ratio
1 Group/ 1 Measure		Descriptive / Detailed One Variable	Descriptive / Detailed One Variable
Independent Data 2 Groups/ 1 Measure >2 Groups/1 Measure		Mann-Whitney U Kruskal-Wallis	Independent Group t-Test One Way ANOVA
Related Data 1 Group/2 Measures (Relation) 1 Group/2 Measures (Gain/Loss) 1 Group/>2 Measures		Spearman Rank Wilcoxon Signed Rank Friedman	Pearson Product Moment (Fisher t-Test) Paired t-Test
1 Group(% Data)/ 1 Group (Raw Data) 2 or >2 Groups Test of Independence	X^2 Goodness of Fit X^2 Test of Independence
	Conditions: 1. Data is in categories and category frequencies are analyzed.	Conditions: 1. Data is ranked and ranks are analyzed.	Conditions: 1. Assume random sample 2. Assume normal curve

      Exercise

      1)Classify each of the following as nominal, ordinal, interval, or ratio level data.

      1)Horsepower of motorcycle engine

      2)Rating of newscasts in Houston as poor, fair, good, excellent

      3)Temperature of outdoors in degrees of Celsius

      4)Time required by drivers to complete a course

      5)Salaries of cashiers of Day-Night convenience store

      6)Political party preference of faculty members

      7)Age of students enrolled in a martial arts course

      8)Weight of beef cattle fed a special diet

      9)Ranking of contestant in a beauty contest

      10)Number of pages in the telephone book for Nashville

      2)In the statements that follow, which are inferential statistics and which are descriptive.

      1)The average price of homes sold in Rhea County during the week of June 6-13 was $83,564.

      2)According to the Census Bureau, 20% of all Americans workers carpool to work.

      3)The National Eye Institute halted a clinical trial on eye surgery, calling it ineffective and possibly harmful to vision.

      4)The Gallup Poll says 1 of every 20 Americans is a member of a Country Club.

      5)Drinking decaffeinated coffee can raise cholesterol levels by 7%.

      6)According to the Court Administrator in Nashville, 10% of the civil actions in 1998 were decided in less than 6 months.

      7)Cigarettes were associated with 29% of the 4,470 civilian fire deaths in 1989.

      3)Critique the statement, “statistics is a language.”

      4)Compare, contrast and illustrate the four functions of statistics – summarizing, describing, generalizing, and experimenting.

      Using This Book

      If the following information is committed to memory at the mastery-level of learning (instant, total recall), a student using this book will be able to conduct statistical research using the Decision Model to determine which statistic to use. Each chapter then can be used to produce a p-value for any hypothesis.

      The Four Questions

      1. Type of data?

      2. Related or Independent data?

      3. How many measures?

      4. How many groups?

      The Four Kinds of Data (NOIR)

Kind	Definition	Examples
Nominal	Naming or Categories	Gender or Political Party
Ordinal	Order or Rank	Horse Race or Likert type scape
Interval	The Intervals are equal	Height, Weight, Distance, Time
Ratio	Interval data with a zero

      Example

      H_o There was a difference in GPA between male and female students.

      1. Type of data? Interval

      2. Related or Independent? Independent (only one measure)

      3. Number of measures? One (GPA)

      4. Number of groups? Two (males and females)

      Using the Decision Model, the correct procedure is the t-Test (Chapter Six).