Levene’s Test in SPSS

1. What is Levene’s Test? Levene’s Test is a statistical test used to assess the equality of variances (homogeneity of variance) across multiple groups. It checks whether different samples have similar variances, which is an important assumption for parametric tests like ANOVA and t-tests. 2. How Levene’s Test Works: 3. Hypotheses: 4. Interpreting the Results: … Read more

Chi-square Independence Test in SPSS

The chi-square independence test is a statistical test used to determine if there is a significant association between two categorical variables. It assesses whether the observed frequencies of the variables in a contingency table differ significantly from the expected frequencies under the assumption of independence. SPSS Data for Chi-square Independence Test This hypothetical data set … Read more

McNemar’s Test in SPSS

This tutorial explains the definition of McNemar’s test, the writing of the null and alternative hypotheses for McNemar’s test, the steps of conducting it in SPSS, and how to interpret the output of McNemar’s test as well as how to report the results. When to Use McNemar’s Test? The McNemar test is used to analyze … Read more

Linear Mixed Models in SPSS

This tutorial includes the explanation of what a linear mixed model is, how to structure its statistical model, data example, as well as steps for linear mixed models in SPSS. Definition of Linear Mixed Models Linear mixed models (LMMs) are statistical models used to analyze data that have both fixed and random effects. They are … Read more

How Dummy and Contrast Codings Impact P-values in SPSS

This tutorial discusses how dummy and contrast codings impact p-values in SPSS for linear regressions. Single Categorical Variable We can start with only one Y (numerical data, or continuous data) and one X (categorical data). We keep it simple to only have 4 observations. The cell means are (3+4)/2=3.5 vs. (5+6)/2=5.5, and the difference is … Read more

Comparisons of t-distribution and Normal distribution

This tutorial compares t-distribution and normal distribution by explaining the similarities and connections between t-distribution and normal distribution. Similarities between t-distribution and normal distribution There are a few similarities between t-distribution and normal distribution. The following figure shows the t-distribution density function curve and the standard normal curve. As we can see, as the sample … Read more

How to change column names of Pandas DataFrames

There are 2 methods of changing the column names of Pandas Dataframes. The following shows the basic Python code syntax for changing column names of Pandas Dataframes. Method 1: df.rename(columns={‘old_name_1′:’new_name_1’, ‘old_name_2′:’new_name_2’}, inplace=True) Method 2: df = df.rename({‘old_name_1′:’new_name_1’, ‘old_name_2′:’new_name_2’}, axis=1) Example 1 of changing column names of Pandas DataFrames (Method 1) The following is the first … Read more

Combine Lists into an Array in Python

You can use Numpy column_stack() or row_stack() to combine lists into an array. As Columns: np.column_stack((list1, list2,…)) As Rows: np.row_stack((list1, list2,…)) Example 1 of lists to columns The following combines lists into an array using column_stack(). Thus, lists become columns in the array. [[6 2 4] [2 1 1] [3 3 2] [4 4 4] … Read more

Check if an item in a Python list

This tutorial shows examples of checking if an item is in a Python list. Method 1: item in list_name Method 2: list_name.index(item) Method 3: list_name.count(item) Example for method 1: Check if an item in a list The following code checks if the item of number 6 is in a list. The following is the output, … Read more

Count the Number of NaN in Pandas Dataframes

This tutorial uses 2 examples to show how to count the number of NaN in Pandas dataframes. Method 1: count the number of NaN by columns: df.isnull().sum() Method 2: count the number of NaN in the whole dataframe: df.isnull().sum().sum() Example for Method 1 The following counts the number of NaN by columns using df.isnull().sum(). The … Read more