ILSAstats (version 0.3.8)

repmean: Mean, Variance and Standard Deviation with Replicate Weights

Description

Estimates the mean, variance and standard deviation with replicate weights for a variable or a group of variables and for one or more populations. For a detailed explanation on how the standard errors are estimated see repse.

Usage

repmean(
  x,
  PV = FALSE,
  setup = NULL,
  repwt,
  wt,
  df,
  method = c("TIMSS", "PIRLS", "ICILS", "ICCS", "PISA", "TALIS"),
  var = c("unbiased", "ML"),
  group = NULL,
  by = NULL,
  exclude = NULL,
  zones = NULL
)

Value

a data frame or a list.

Arguments

x

a string vector specifying variable names (within df) for analysis.

PV

a logical value indicating if the variables in x are plausible values.

setup

an optional list produced by repsetup.

repwt

a string indicating the common names for the replicate weights columns (within df), or a data frame with the replicate weights.

wt

a string specifying the name of the column (within df) with the total weights.

df

a data frame.

method

a string indicating the name of the large-scale assessment to determine the replication method to use. Available options are: "TIMSS", "PIRLS", "ICILS", "ICCS", "PISA", and "TALIS". Note that "TIMSS" and "PIRLS" refer to the method used from 2016 onwards. Their method has not yet been implemented for previous cycles.

var

a string indicating the method to use for the variance: "unbiased" calculates the unbiased estimate (n-1); "ML" calculates the maximum likelihood estimate.

group

a string specifying the variable name (within df) to be used for grouping. Categories in group are treated as independent, e.g., countries.

by

a string specifying a second variable (within df) for grouping. Categories used in by are not considered independent, e.g., gender within a country. If used, the output will be a list with the same length as the unique values of by. This can only be used for analyses with one variable or a group of PVs.

exclude

a vector indicating which groups (in the same format as group) should be excluded from the pooled and composite estimates.

zones

a string specifying the name of the variable containing the replicate zones. Used for calculating the number of zones to be used by variable and group. If NULL, zones are not be calculated.

Examples

# Creation of replicate weights
RW <- repcreate(df = repdata, # the data frame with all the information
                 wt = "wt", # the total weights column name
                 jkzone = "jkzones", # the jkzones column name
                 jkrep = "jkrep", # the jkreps column name
                 repwtname = "REPWT", # the desired name for the rep weights
                 reps = 50, # the number of replications
                 method = "ICILS") # the name of the method aka the study name

### No groups ----

# One variable - weights within df
repmean(x = c("item01"),
        PV = FALSE,
        repwt = "REPWT", wt = "wt", df = cbind(repdata,RW),
        method = "ICILS",var = "ML",zones = "jkzones")

# One variable - weights as a separate data frame
repmean(x = c("item01"),
        PV = FALSE,
        repwt = RW, wt = "wt", df = repdata,
        method = "ICILS",var = "ML",zones = "jkzones")

# Multiple variables
repmean(x = c("item01","item02","item03"),
        PV = FALSE,
        repwt = RW, wt = "wt", df = repdata,
        method = "ICILS",var = "ML",zones = "jkzones")

# One PV variable
repmean(x = paste0("Math",1:5),
        PV = TRUE, # if set to TRUE, PVs will be treated as separate variables
        repwt = RW, wt = "wt", df = repdata,
        method = "ICILS",var = "ML",zones = "jkzones")

### Groups ----

# One variable
repmean(x = c("item01"),
        PV = FALSE,
        repwt = RW, wt = "wt", df = repdata,
        method = "ICILS",var = "ML",zones = "jkzones",
        group = "GROUP",
        exclude = "GR2") # GR2 will not be used for Pooled nor Composite

# Multiple variables
repmean(x = c("item01","item02","item03"),
        PV = FALSE,
        repwt = RW, wt = "wt", df = repdata,
        method = "ICILS",var = "ML",zones = "jkzones",
        group = "GROUP",
        exclude = "GR2") # GR2 will not be used for Pooled nor Composite

# One PV variable
repmean(x = paste0("Math",1:5),
        PV = TRUE, # if set to TRUE, PVs will be treated as separate variables
        repwt = RW, wt = "wt", df = repdata,
        method = "ICILS",var = "ML",zones = "jkzones",
        group = "GROUP",
        exclude = "GR2") # GR2 will not be used for Pooled nor Composite

### Groups and By ----

# One variable
repmean(x = c("item01"),
        PV = FALSE,
        repwt = RW, wt = "wt", df = repdata,
        method = "ICILS",var = "ML",zones = "jkzones",
        group = "GROUP",
        by = "GENDER", # results will be separated by GENDER
        exclude = "GR2") # GR2 will not be used for Pooled nor Composite

# One PV variable
repmean(x = paste0("Math",1:5),
        PV = TRUE, # if set to TRUE, PVs will be treated as separate variables
        repwt = RW, wt = "wt", df = repdata,
        method = "ICILS",var = "ML",zones = "jkzones",
        group = "GROUP",
        by = "GENDER", # results will be separated by GENDER
        exclude = "GR2") # GR2 will not be used for Pooled nor Composite