Goal 3

Test of hypothesis

One of the more difficult skills in data analysis is deciding which statistical models and tests to use in a particular situation. 

The choice of statistical model/test is affected by two things:

  1. The kind of question we are asking.

  2. The nature of data we have:

    • what type of variables: ratio, interval, ordinal or nominal?

    • are the assumptions of a particular model or test satisfied by the data?

The schematic key (below) provides a overview of the statistical models and tests we’ve covered in this book, structured in the form of a key. The different choices in the key are determined by a combination of the type of question being asked, and the nature of the data under consideration.

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Market Analysis

Test of normality - Awards example

The number of awards earned by students at one high school. Predictors of the number of awards earned include the type of program in which the student was enrolled (e.g., vocational, general or academic) and the score on their final exam in math. This data set is used to show an example of the Poisson Regression. The predicted variable is the number of awards and the predictors are the program type and the Maths score.

Suggested tests

Descriptive statistics

Skewed data

Kruskall-Wallis test

Poisson regression

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T-test - Cholesterol example

A study tested whether cholesterol was reduced after using a certain brand of margarine as part of a low fat, low cholesterol diet. The subjects consumed on average 2.31g of the active ingredient, stanol easter, a day. This data set contains information on 18 people using margarine to reduce cholesterol over three-time points. The data set can be used to demonstrate paired t-tests, repeated measures ANOVA and a mixed between-within ANOVA using the final variable ‘Margarine’. The dataset is also good for discussion about meaningful differences as the difference between weeks 4 and 8 is very small but significant

Suggested tests

Descriptive statistics

Recoding and computing new variables

T-tests

ANOVA: within groups & repeated measures

o99iqkkau79-hypothesis-testing.jpeg

Mann-Whitney U test - Crime example

This data set gives a variety of variables by US state at two time points 10 years apart. A variety of regressions and t-tests can be carried out with the main scale dependent being and Crime Rate (offences per million population) and t-tests with the independent being whether or not the state is in the south. Mostly discrete variables as they measure populations per 1000, there are some continuous variables such as those measuring expenditure

Suggested tests

Descriptive statistics

Skewed data

Recoding and computing new variables

T-tests

Mann-Whitney U test

Scatterplots and correlation

Simple linear and multiple regression

Chi-squared test

Cluster analysis

o99iqkkau79-hypothesis-testing.jpeg

Paired samples t-test - students volunteer example

A teacher developed 3 exams for the same course. He needs to know if they're equally difficult so he asks his students to complete all 3 exams in random order. Only 19 students volunteer. Their data -partly shown below- are in compare-exams.sav. They hold the number of correct answers for each student on all 3 exams.

Suggested tests

Descriptive statistics

Skewed data

One-sample t-test

Mann-Whitney U test

Two samples t-test

Paired samples t-test

o99iqkkau79-hypothesis-testing.jpeg

ANOVA: one & two-way - Diets example

This data set contains information on 78 people using one of three diets. The dataset is primarily used for ANOVA.

Suggested tests

Descriptive statistics

Skewed data

One-sample t-test

Mann-Whitney U test

Two samples t-test

Paired samples t-test

Research #2

The national accreditation program in Kuwait: its development, implementation and impact on quality improvement in public hospitals.  

Graphs

Research #3

Absenteeism- is a major expense to most organizations. Getting a handle on it, predicting it and affecting it is important for organizations. This dataset provided for HR data scientists to practice on

Inspiration

1- Describe the data set

2- Insight the most Absenteeism features

3- Report the analysis 

Arabic document

Here you can find some SPSS books and notes

Arabic Article 

Here you can find the most useful article that guide you how to choose the most appropriate statistical test

Statistical Analysis

Here you can find a map that will help you to follow the best track for statistical analysis in SPSS

Best website

Here you can find the best website to help you in how to perform the statistical analysis using SPSS step by step