Q1 Homework Null Hypothesis

Practice Homework -- Identify Dependent and Independent Variables, the data types, the statistical procedure, the theory and the Null Hypothesis

Homework -- The Null Hypothesis for differing Data-type combinations

The effect of additional police on number of crimes

Is there a difference in average (mean) number of victimizations between violent offenders and non-violent offenders?

In a study of inmates, do additional prior arrests affect the sentence length?

Is there a difference in average (mean) scores on the GRE test between a sample of Criminal Justice students at NG compared to the population of Criminal Justice students nationwide?

Is the “count of students” in a single variable higher among two categories: traditional or non-traditional Criminal Justice students?

 Is there a difference in the number of average (mean) arrests between Hispanics, African Americans, and Caucasians?

Will the “average (mean) number of illegal immigrants” after a border tightening policy be less than before the policy was in effect?

Is there a difference in the count of persons belonging to political "party affiliation” (republican or democrat) between males and females?

What is the predicted LSAT score of a law-school student who scores 156 on the IQ test?

Is there a difference in average (mean) scores on the Minnesota Multi-Phasic Personality Inventory (MMPI test) between military and civilians?

Is there is a difference in average (mean) income between different ethnic groups: white and nonwhite police officers.

A researcher conducted a study on job satisfaction between two employers:  Federal employees and city/state employees.  He has heard that federal jobs are more desirable, so he devised a job-satisfaction scale from 1 to 10, (1 = very dissatisfied, 10 = very satisfied), to ascertain if employer type made a difference in job satisfaction.

Who has more average (mean) repeat offenses, inmates under age-40 or inmates age-40 and over?

A social worker theorizes that higher levels of parental education lessens the frequency of the child’s delinquency.  

It is commonly theorized that liberals donate more money on average (mean) to charity than do conservatives.

A social scientist believes that, because married adults have the potential for two incomes, they will have more average (mean) disposable income than single adults.

A political scientist is asked to research landslide winners in political contests (Governors were surveyed). The goal is to discover if “popularity in elections” is related to job effectiveness. He gathers data on how many “votes” were received by both candidates in the 50 state elections over the past 3 years, and how many “executive actions” the winner took while in office. 

Is happiness in marriage related to income level? A researcher asked 40 subjects to rate their “marriage happiness” (rated on a scale of 1 to 6, 1 being near divorce and 6 being blissful), and the couple’s yearly income.

A CJ major is trying to find out if the crime rate is higher in areas with one or two officer patrols. It is theorized that the average (mean) “crime,” is higher in one-officer “patrols.” She collects data from 35 districts.

Certain special interest groups have convinced many voters through a media campaign that ethnic minority couples typically have more children on average (mean)  than Caucasian couples.

A Researcher wants to determine the relationship between hours spent viewing television and education.

A drug identification unit wants to determine the “reaction time in seconds” between amphetamine users and those on placebos.

Child misbehavior (did or did not) was studied between working mothers and stay-at-home mothers

A follow-up study was conducted to ascertain the difference in average (mean) “GPA” between children that grew up at daycare facilities and those that grew up at home.

A study was conducted to test the theory that high levels of “crime” are associated with low levels of “income.” 

A study was conducted to test the theory that high levels of “crime” are associated with low levels of “income.”

Homework – Problems

From the list below, identify the data-type combination and choose the correct procedure based on the study design.

a.  Pearson r,  b. Bivariate regression, c. Independent sample t-test,

d. Paired-sample t-test, e. One-Sample t-test, f. One-way Chi-Square, g. Two-Way Chi-square

h. Analysis of Variance (ANOVA)

Example:  Is there a difference in the dependent variable mean “number of victimizations” among inmates between violent offenders and non-violent offenders?

  ___Metric_                            _Nominal_                                 _Independent Samples t-test

  Dependent Variable       Independent Variable                                     Statistical Procedure

1.  In a study of inmates, does the mean arrests effect the dependent variable mean sentence length?

        ____________                    ____________                        ________________________________

  Dependent Variable       Independent Variable                                     Statistical Procedure

2.  Is there a difference in the dependent variable “GRE scores” between Criminal Justice students at UNG compared to the population of Criminal Justice students nationwide?

        ____________                    ____________                        ________________________________

  Dependent Variable       Independent Variable                                     Statistical Procedure

3.  Is the dependent variable “count of students” higher among traditional or non-traditional Criminal Justice students?

       ____________                    ____________                        ________________________________

  Dependent Variable       Independent Variable                                Statistical Procedure

4.  Is there a difference in the dependent variable “mean number of arrests” between Hispanics, African Americans, and Caucasians?

        ____________                    ____________                        ________________________________

  Dependent Variable       Independent Variable                                     Statistical Procedure

5.  Will the dependent variable “mean number of illegal immigrants” after a border tightening policy be less than before the policy was in effect?

        ____________                    ____________                        ________________________________

  Dependent Variable       Independent Variable                                     Statistical Procedure

6.  Is there a difference in the dependent variable “count in political party affiliation” (republican or democrat) between males and females?

        ____________                    ____________                        ________________________________

  Dependent Variable       Independent Variable                                     Statistical Procedure

7.  What “LSAT score” (dependent variable) is a Law student who has an IQ of 156 predicted to attain?

        ____________                    ____________                        ________________________________

  Dependent Variable       Independent Variable                                     Statistical Procedure

8.  Is there a difference in the dependent variable mean “Minnesota Multi-Phasic Personality Inventory (MMPI)” score between military and civilians?

        ____________                    ____________                        ________________________________

  Dependent Variable       Independent Variable                                     Statistical Procedure

a.  Pearson r,  b. Bivariate regression, c. Independent sample t-test,

d. Paired-sample t-test, e. One-Sample t-test, f. One-way Chi-Square, g. Two-Way Chi-square

h. Analysis of Variance (ANOVA)

Answers

1.  In a study of inmates, does the mean arrests effect the dependent variable mean sentence length?

  Metric                                          Metric                                                       _Pearson r_

  Dependent Variable       Independent Variable                                     Statistical Procedure

2.  Is there a difference in the dependent variable “GRE scores” between Criminal Justice students at UNG compared to the population of Criminal Justice students nationwide?

          Metric                           Nominal  (sample/population)               _One-Sample t-test_

  Dependent Variable       Independent Variable                                     Statistical Procedure

3.  Is the dependent variable “count of students” higher among traditional or non-traditional Criminal Justice students?

        Count                                  Nominal                                                 _One-way Chi-square_

  Dependent Variable       Independent Variable                                     Statistical Procedure

4.  Is there a difference in the dependent variable “mean number of arrests” between Hispanics, African Americans, and Caucasians?

         Metric                               Nominal                                                   Analysis of Variance_

  Dependent Variable       Independent Variable                                     Statistical Procedure

5.  Will the dependent variable “mean number of illegal immigrants” after a border tightening policy be less than before the policy was in effect?

             Metric                        Nominal (Before and After)                         _Paired-Sample t-test_    

  Dependent Variable       Independent Variable                                     Statistical Procedure

6.  Is there a difference in the dependent variable “count in political party affiliation” (republican or democrat) between males and females?

         Nominal                                Nominal                                              Two-Way Chi-Square_

  Dependent Variable       Independent Variable                                     Statistical Procedure

7.  What “LSAT score” (dependent variable) is a Law student who has an IQ of 156 predicted to attain?

         Metric                                     Metric                                             _Bivariate Regression_

  Dependent Variable       Independent Variable                                     Statistical Procedure

8.  Is there a difference in the dependent variable mean “Minnesota Multi-Phasic Personality Inventory (MMPI)” score between military and civilians?

            Metric                               Nominal                                       _Independent-Sample t-test_

     Dependent Variable       Independent Variable                                     Statistical Procedure