Case Semantics & Transforms

Two related ideas: case semantics change which cases an analysis sees and how much each counts, and transforms create or reshape variables. Both live under the Data and Transform menus, and both are respected by every analysis automatically.

These three settings travel with every analysis, chart and transform you run. The status bar shows when any of them is active.

Select Cases

Data → Select Cases… (Ctrl+Alt+S). Restrict the analysis to a subset of cases — for example, only participants where Age >= 60, or a random sample. Unselected cases are filtered out of every subsequent statistic until you clear the selection. You can choose to filter (hide) or to mark unselected cases.

Weight Cases

Data → Weight Cases… (Ctrl+Alt+W). Give each case a frequency weight from a variable, so a case with weight 3 counts as three observations. Used for data stored as a frequency table, or to apply survey weights. Counts, means and tests all honour the weight.

Split File

Data → Split File… (Ctrl+Alt+T). Repeat every analysis separately for each group of a categorical variable — e.g. run all your descriptives once per StudyZone. Output is produced per split group until you turn the split off.

Order of operations. Select narrows the cases, Weight scales their counts, and Split partitions the result into groups — and every analysis you run sees all three at once.

Transforms (Transform & Data menus)

Compute Variable

Transform → Compute Variable… (Ctrl+Shift+C). Create a new variable (or overwrite one) from an expression. The expression language is missing-aware and typed (number, string or date):

Arithmetic — + - * /, parentheses, MOD.
Numeric functions — SQRT, LN, LOG10, EXP, ABS, MIN, MAX, the trig family, ROUND(x[, digits]), and the SD / VARIANCE aggregates.
Logic — comparisons (< <= > >= = ~=), AND OR NOT, and IF(cond, then, else).
String — CONCAT, LENGTH, UPCASE, LOWCASE, LTRIM, RTRIM, SUBSTR, INDEX, REPLACE, STRING, NUMBER, and quoted literals.
Date (ISO YYYY-MM-DD) — DATE.DMY, DATE.MDY, YEAR, MONTH, DAY, DATEDIFF.

The new variable takes the type of its expression — a string expression makes a string variable, a date expression a date variable.

Example. BMI_category = IF(BMI >= 30, "Obese", IF(BMI >= 25, "Overweight", "Normal")).

Recode

Transform → Recode… (Ctrl+Shift+R). Map a variable's values into new ones — into the same variable or a new one. Use it to collapse categories (e.g. five education levels into three) or to band a scale variable.

Grouping a scale variable vs. histogram bins

Two things look alike but do different jobs:

The histogram's bins slider groups a scale variable in the picture only — display, no data change. Use it to explore shape.
A Recode into Different Variables (or Bin Variable, below, for the common numeric-cutpoints case) makes a real categorical variable (BMI → Underweight/Normal/Overweight/Obese) that crosstabs, boxplots and ANOVA can use, and that is saved with the document. Use it when the groups are part of the analysis.

The tutorial workbook's transforms module walks this exact recode end to end.

Rank Cases

Transform → Rank Cases… (Ctrl+Shift+K). Create a new variable holding each case's rank on a chosen variable, with the usual tie-handling options.

Bin Variable

Transform → Bin Variable… (Ctrl+Shift+N). The purpose-built front end for grouping a scale variable into a new ordinal one — Recode works for this too, but means typing every cutpoint and label by hand. Pick a variable and a method:

Equal width — N groups of equal size along the value range (e.g. four 10-point-wide BMI bands).
Equal count (quantiles) — N groups with (about) the same number of cases in each, e.g. splitting into quartiles.
Custom — your own ascending cutpoints (e.g. 18.5, 25, 30 for the standard BMI categories).

A live preview shows the resolved boundaries as cut lines over a histogram of the variable, and the generated group labels (< 18.5, 18.5 – 25, …), before you commit. The new variable is numeric with Ordinal measure and value labels already set — nothing left to finish in Variable View. Cutpoints are resolved against the currently active Select Cases/Weight Cases, like every analysis.

Sort Cases (Ctrl+Shift+D) — reorder rows by one or more variables.
Transpose (Ctrl+Alt+P) — swap rows and columns.
Merge Files (Ctrl+Alt+M) — add cases or add variables from another dataset, matched by a key.
Define Variable Properties (Ctrl+Alt+D), Bulk Rename and Variable Sets — covered in Working with Data.

Reproducibility note

Compute, Rank, Sort and Bin Variable are journalled — they appear in the Syntax console as commands, so a data-preparation pipeline can be saved and replayed on fresh data exactly. Bin Variable's journaled command always records the resolved cutpoints, even for the Equal width/Equal count methods — so replaying it later reproduces the same groups rather than silently re-deriving different ones from changed data. Recode is the deliberate exception: its ordered rule list does not reduce to a one-line command, so it stays a dialog transform — the recoded variable itself is preserved by saving the .ckd.