merge_surveys: Merge and harmonize surveys

In retroharmonize: Ex Post Survey Data Harmonization

Merge and harmonize surveys

Description

'merge_surveys()' applies a harmonization specification to a list of survey objects and returns harmonized survey datasets with aligned variable names and metadata.

Usage

merge_surveys(survey_list, var_harmonization)

Arguments

survey_list	A list of survey objects.
var_harmonization	A metadata table describing the harmonization rules. The table must contain at least: - 'filename' - 'var_name_orig' - 'var_name_target' - 'var_label'

Details

Harmonize variable names, labels, and identifiers across multiple surveys using a metadata crosswalk table.

Prior to version 0.2.0 this function was called 'merge_waves()', reflecting terminology commonly used in Eurobarometer surveys.

The harmonization table supplied in 'var_harmonization' typically originates from [metadata_create()] and contains mappings between original and harmonized variable names.

Value

A list of harmonized survey objects with standardized variable names and variable labels.

See Also

[metadata_create()]

Other survey harmonization functions: merge_waves()

Examples

examples_dir <- system.file(
  "examples",
  package = "retroharmonize"
)

survey_files <- dir(
  examples_dir,
  pattern = "\\.rds$",
  full.names = TRUE
)

example_surveys <- read_surveys(
  survey_files
)

metadata <- metadata_create(
  survey_list = example_surveys
)

to_harmonize <- metadata %>%
  dplyr::filter(
    var_name_orig %in% c("rowid", "w1") |
      grepl("^trust", var_label_orig)
  ) %>%
  dplyr::mutate(
    var_label = var_label_normalize(var_label_orig),
    var_name_target = val_label_normalize(var_label),
    var_name_target = ifelse(
      .data$var_name_orig %in%
        c("rowid", "w1", "wex"),
      .data$var_name_orig,
      .data$var_name_target
    )
  )

merged_surveys <- merge_surveys(
  survey_list = example_surveys,
  var_harmonization = to_harmonize
)

merged_surveys[[1]]

retroharmonize documentation built on May 21, 2026, 9:06 a.m.