buckwalter2010knowledgeisntclosed
/data/papers/buckwalter2010knowledgeisntclosed/analysis/effect_sizes.qmd---
title: "Effect size computations: buckwalter2010knowledgeisntclosed"
format:
html:
toc: true
execute:
echo: true
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---
Computes standardized mean differences (`d`) and sampling variances (`v`) for the
extraction YAML `papers/buckwalter2010knowledgeisntclosed/buckwalter2010knowledgeisntclosed.yaml`.
## Inputs and methods
```{r}
paper_key <- "buckwalter2010knowledgeisntclosed"
sign_convention <- "d = mean(low) - mean(high)"
effects <- list(
list(
study_id = 1,
effect_id = "s1_e1",
method_used = "between_groups",
n_low = 183,
n_high = 181,
mean_low = 3.83,
mean_high = 3.71,
sd_low = 1.065,
sd_high = 1.108,
notes_on_assumptions = "Table 1: Bank (low stakes) vs High Stakes (high stakes)."
),
list(
study_id = 1,
effect_id = "s1_e2",
method_used = "between_groups",
n_low = 183,
n_high = 180,
mean_low = 3.83,
mean_high = 3.64,
sd_low = 1.065,
sd_high = 1.102,
notes_on_assumptions = "Table 1: Bank (low standards/no skeptical pressure) vs High Standards (skeptical pressure)."
)
)
```
## Computation
```{r}
default_or <- function(x, default) {
if (is.null(x)) default else x
}
stop_if_missing <- function(x, name) {
if (is.na(x)) stop(sprintf("Missing required input: %s", name), call. = FALSE)
}
# Exact small-sample correction factor used by metafor (.cmicalc).
hedges_correction <- function(df) {
ifelse(df <= 1, NA_real_, exp(lgamma(df / 2) - log(sqrt(df / 2)) - lgamma((df - 1) / 2)))
}
pooled_sd <- function(n_high, n_low, sd_high, sd_low) {
sqrt(((n_high - 1) * sd_high^2 + (n_low - 1) * sd_low^2) / (n_high + n_low - 2))
}
d_from_groups_independent <- function(n_high, n_low, mean_high, mean_low, sd_high, sd_low) {
s <- pooled_sd(n_high, n_low, sd_high, sd_low)
(mean_low - mean_high) / s
}
var_d_independent <- function(d, n_high, n_low) {
n <- n_high + n_low
(n / (n_high * n_low)) + (d^2 / (2 * (n - 2)))
}
compute_effect <- function(effect_inputs) {
study_id <- effect_inputs$study_id
effect_id <- effect_inputs$effect_id
method_used <- effect_inputs$method_used
n_high <- default_or(effect_inputs$n_high, NA_integer_)
n_low <- default_or(effect_inputs$n_low, NA_integer_)
mean_high <- default_or(effect_inputs$mean_high, NA_real_)
mean_low <- default_or(effect_inputs$mean_low, NA_real_)
sd_high <- default_or(effect_inputs$sd_high, NA_real_)
sd_low <- default_or(effect_inputs$sd_low, NA_real_)
notes_on_assumptions <- default_or(effect_inputs$notes_on_assumptions, "")
if (method_used != "between_groups") {
stop(sprintf("This paper uses between_groups only; got method_used=%s", method_used), call. = FALSE)
}
stop_if_missing(n_high, "n_high")
stop_if_missing(n_low, "n_low")
stop_if_missing(mean_high, "mean_high")
stop_if_missing(mean_low, "mean_low")
stop_if_missing(sd_high, "sd_high")
stop_if_missing(sd_low, "sd_low")
d <- d_from_groups_independent(n_high, n_low, mean_high, mean_low, sd_high, sd_low)
v <- var_d_independent(d, n_high, n_low)
df_used <- n_high + n_low - 2
J <- hedges_correction(df_used)
g <- J * d
v_g <- (J^2) * v
inputs_used <- paste(
c(
sprintf("method=%s", method_used),
sprintf("sign_convention=%s", sign_convention),
sprintf("n_low=%s", n_low),
sprintf("n_high=%s", n_high),
sprintf("mean_low=%s", mean_low),
sprintf("mean_high=%s", mean_high),
sprintf("sd_low=%s", sd_low),
sprintf("sd_high=%s", sd_high)
),
collapse = ", "
)
data.frame(
paper_key = paper_key,
study_id = study_id,
effect_id = effect_id,
design = "Between-Subjects",
method_used = method_used,
computed_from_suggested = "groups",
inputs_used = inputs_used,
d = d,
v = v,
g = g,
v_g = v_g,
notes_on_assumptions = notes_on_assumptions,
stringsAsFactors = FALSE
)
}
audit <- do.call(rbind, lapply(effects, compute_effect))
audit
```
## Paste-ready YAML snippets
```{r}
for (i in seq_len(nrow(audit))) {
row <- audit[i, ]
cat(sprintf("\n# %s (study_id=%s)\n", row$effect_id, row$study_id))
cat(sprintf(
"effect_size:\n metric: SMD\n d: %.12f\n v: %.12f\n computed_from: %s\n needs_review: false\n notes: \"%s\"\n",
row$d,
row$v,
row$computed_from_suggested,
gsub("\"", "'", row$inputs_used)
))
}
```