Biostatistics Laboratory - Week 2&3

• SPSS - Statistical Package for the Social Sciences
• 1968 - SPSS was first launched
• 2009 - SPSS was aquired by IBM, making it officially known as IBM SPSS Statistics.
• SPSS - a software for editing and analyzing all sorts of data.
• Sources of SPSS data - scientific research, a customer database, Google Analytics, or even the server log files of a website.
• .sav - file serving format of SPSS Data Editor.
• Variable view - shows the metadata associated with the data.

  
• Metadata - information about the meaning of variables and data values. The "dictionary" in SPSS.
• The variable name is used to identify the column containing the data. It can be up to eight characters long.
• The label provides additional information on what the variable represents.
• Width specifies how many digits are allowed for this variable.
• Value labels are used when there are only a few possible values that need to be described more fully.
• Output viewer window - holds a table with all statistics on all chosen variables

  
• Data view - displays data values in a spreadsheet fashion.

  
• Descriptive Statistics - a tab that allows you to analyze your data in SPSS by showing a selection of variables and statistics one wants to inspect.

  
• Syntax editor window - a third window in which we can type and run SPSS code known as SPSS syntax. Allows to create a syntax that can be saved, corrected, rerun and shared between projects or users.

  
• Syntax makes SPSS work replicable.
• SPSS is great for: opening data files, editing data, creating tables and charts, inferential statistics, saving data and outputs.
• SPSS contains all basic statistical tests and multivariate analyses such as: t-tests, chi-square tests, ANOVA, correlations, regression, nonparametric tests, factor analysis, and cluster analysis.
• SPSS can be saved in a variety of file formats including: MS Excel, plain text (.txt or.csv), Stata, SAS.
• Variable measures - Nominal, Ordinal, Scale, String
• Nominal - pertains to a category, a number, or a name. It is recorded using "Frequency" and a "Bar Graph".
• Dichotomous - a variable with only two categories.
• Scale - an SPSS measure that represents quantitative variables which are at ratio level. It should be recorded using mean, standard deviation, and a histogram.
• String - a variable containing characters such as letters, numbers, punctuation marks, etc.
• Analyze menu - runs an analysis on SPSS.
• Frequencies - shows all the variables on the data set and the variables to be analyzed.
• Data Editor - displays the raw data from the dataset.
• Output window - displays output generated by running a command.
• Variable View - allows us to change the name or label of our variables.
• Value Labels - allows us to assign labels to specific values within a categorical variable.
• Missing Values - allows us to specify missing values for any variable.
• Valid - values that represent participants with scores.
• Chart builder - displays a preview of the chart on the canvas.
• Graph Builder - creates charts based on selected variables.
• cases - represent individual respondents to a survey.
• Variables - represent responses to each question asked in the survey.
• Labels can be up to 255 bytes.
• Value labels - provide a method for mapping your variabe values to a string label.
• Missing data is represented by a period (.)