Brief Overview of STATCAL Statistical Application Program
Prana Ugiana Gio
Currently, there are many application programs to perform statistical analysis, such as SPSS, EViews, and Minitab, which are commercial software, while PSPP, JASP and PAST, which are free software. STATCAL is an user-friendly statistical application program which is developed using R programming language, in RStudio using various R packages. STATCAL is designed as simple as possible so that only need a bit of step to obtain result. Various statistical tests in STATCAL, such as normality, homogeneity, comparison of two or more means, correlation, association between categorical variables, reliability, linear regression, panel data regression, covariance-based structural equation modeling and partial least square path modeling are available. Inside STATCAL is also provided tutorial video and guidance menu to make easy for user.
There are two alternatives to use statistical application program, namely free or commercial statistical application program. Commercial statistical application program such as SPSS, EViews and Minitab, while free statistical application program such as PSPP, JASP, and PAST. STATCAL is also statistical application program which is free. STATCAL is created using R programming language in RStudio using various R packages (https://statcal.info/r-packages-in-statcal/) to perform graphical and statistical analysis. STATCAL is created by Prana Ugiana Gio, on January 2017, and continuing to be developed until now. STATCAL has core team, namely Dina Nazriani, Meigia Nidya Sari, Rizki Syahputra, Anil Hakim Syofra, Puteri Anggi and Rezzy Eko Caraka. STATCAL is an user-friendly statistical application program which is designed as simple as possible so that only need a few step to obtain result. STATCAL can be used by online accessing http://gioprana.shinyapps.io/STATCAL or can be downloaded in https://statcal.info/download-statcal/. One of difference STATCAL with other statistical application program is tutorial video and guidance menu can be accessed directly inside STATCAL, so that make easy for user. Covariance-based structural equation modeling and partial least square path modeling are also available in STATCAL.
2. Getting Started STATCAL
Figure 1 is an initial appearance when STATCAL statistical application program is run.
Figure 1 Initial Appearance in STATCAL
There are nine main menus. STATCAL menu explains brief description about STATCAL. STATCAL has two areas to input data, namely for numeric and categorical data, that will be explained in subsequent section. Various graphs, such as bar, line, circle, scatter plot, and boxplot, can be formed in Graph menu. Descriptive measures, frequency and percentage distribution are available in Descriptive menu. Various statistical tests can be accessed in Statistics menu. Probability menu can generate random number based on certain probability distribution, such as normal and t distribution and then these random numbers can be presented in to bar chart or histogram. For user who is first time uses STATCAL, Tutorial Video and Guidance menu will help how to use STATCAL.
2.1 Data Preparation
First step before entering data in STATCAL is data preparation. Data preparation in this illustration uses Microsoft Excel. Data in Microsoft Excel will be copied and pasted to STATCAL later. Figure 2 is an example of simple data which contains three parts. In part I, there are two categorical variables, namely gender and blood. Part II displays value and label based on part I. For instance, value 1 in gender states male, while value 2 states female. Part III contains two numeric variables, namely height and weight. Based on Figure 2, consider that there are two colors, pink and yellow. Data in yellow region will be copied and pasted in to STATCAL later.
Figure 2 Data Preparation in Microsoft Excel
2.2 Step by Step to Input Categorical Data in STATCAL
In this part will be explained how to enter categorical data in STATCAL. In the previous section, data has been prepared in Microsoft Excel. Now, data in yellow region for part I and part II is copied and pasted to STATCAL (Figure 3). Figure 3 displays categorical data has been entered in STATCAL. First, consider part of Set Number of Column. In this part is asked to enter number of categorical variable. Number of categorical variable is 2, but it can be filled with 3, 4, 5 or a number greater than 2. This is because perhaps exists addition of variable later. So Set Number of Column part is filled with 20. Second, consider Set Number of Row part. The number of observation is 10. But it can be filled 11, 13, 1000 or a number greater than 10. Enter name of categorical variable in Name of Variable part. The last part is Label. In this part, enters the label for each categorical variable. For example for gender variable, value 1 states male and value 2 states female. For blood variable, value 1 states A, value 2 states B, value 3 states AB and value 4 states O.
Figure 3 Input Categorical Data
2.3 Is Correct Your Categorical Data Input?
In the previous part has been explained step by step how to enter categorical data in STATCAL. But, is correct your categorical data input? How to check it? To ensure it, move to Your Categorical Data part (Figure 4). In this part displays again categorical data but the data has been converted become label. Check, is there any mistake?
Figure 4 Examination of Categorical Data Input
2.4 Your Categorical Data Input is Wrong and Not Available Data
Figure 5 is an example when categorical data input is wrong. For example observation of row 8 and column 1 (gender variable) is replaced with 4. In Your Categorical Data part will display "Error: `from` and `to` vectors are not the same length.". This is because there are only two labels in gender variable, namely male and female, while there are three kind of numbers 1, 2 and 4. For example observation of row 8 and column 1 (gender variable) is not filled or empty (Figure 6). Now, consider Your Categorical Data part, observation of row 8 and column 1 is filled with
Figure 5 Example of When Categorical Data Input is Wrong
Figure 6 Example of Not Available Data
2.5 Step by Step to Input Numeric Data in STATCAL
The final stage is how to input numeric data in STATCAL. This is simpler than input categorical data. Based on Figure 2, copies numeric data, namely part III for yellow region and moves to Input Numeric Data menu (Figure 7). Consider part of Set Number of Column. In this part will be filled with a value representing the number of numeric variable. The number of numeric variable is 2, but in this part can be filled with a number which is greater than 2. In this illustration is filled with 20. This is because anytime perhaps will exist addition of variable. Now consider the part of Set Number of Row. For the Set Number of Row part is filled with a value representing the number of observation. The number of observation is 10, but it can be filled with a number which is greater than 10. Based on Figure 7, Set Number of Row part is filled with 40. In part of Name of Variable is filled with name of numeric variable.
Figure 7 Input Numeric Data
Prana Ugiana Gio, STATCAL CEO