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Run an Independent-Samples t-Test with Automated Narrative Reporting

Source: R/easy_ttest.R
easy_ttest.Rd

Executes a two-sample (or one-sample) t-test using stats::t.test(), extracts key metrics via broom, and generates a plain-language narrative via the Narrative Generator Module.

Usage

easy_ttest(
  x,
  y = NULL,
  data = NULL,
  mu = 0,
  var.equal = FALSE,
  conf.level = 0.95,
  alpha = 0.05
)

Arguments

x

A numeric vector, OR a formula of the form outcome ~ group when data is provided.

y

A numeric vector (second group) when x is not a formula. Ignored when x is a formula.

data

A data frame. Required when x is a formula.

mu

Null hypothesis value for the mean (one-sample test). Default 0.

var.equal

Logical; assume equal variances? Default FALSE (Welch).

conf.level

Confidence level. Default 0.95.

alpha

Significance threshold for narrative. Default 0.05.

Value

An object of class "easystat_result" with:

test_type

Character: "ttest"

formula_str

Description of the comparison

raw_model

The raw htest object

coefficients_table

Group means and confidence interval

model_fit_table

t-statistic, df, and p-value

explanation

Plain-language narrative string

Examples

result <- easy_ttest(mpg ~ am, data = mtcars)
print(result)
#> 
#> ================================================================================
#>  EasyStat Result :: TTEST
#> ================================================================================
#> 
#> TABLE 1 — MAIN RESULTS
#> --------------------------------------------------------------------------------
#>          Metric Label    Value
#>  Mean (Group 1)     0  17.1474
#>  Mean (Group 2)     1  24.3923
#>  95% CI (lower)     - -11.2802
#>  95% CI (upper)     -  -3.2097
#> 
#> TABLE 2 — MODEL FIT / SUMMARY
#> --------------------------------------------------------------------------------
#>              Metric   Value
#>         t-statistic -3.7671
#>  Degrees of Freedom   18.33
#>             p-value 0.1374%
#> 
#> ================================================================================
#>  PLAIN-LANGUAGE INTERPRETATION
#> ================================================================================
#> 
#> INDEPENDENT-SAMPLES t-TEST Comparison: mpg ~ am
#> 
#> An independent-samples t-test revealed a statistically significant (p =
#>   0.1374%) difference between the two groups (t(18.33) = -3.767). The mean
#>   for '0' was 17.1474 and the mean for '1' was 24.3923. The 95% confidence
#>   interval for the difference in means ranged from -11.2802 to -3.2097. These
#>   results provide statistically significant evidence that '0' and '1' differ
#>   meaningfully on the measured variable.
#> 
#> ================================================================================
#>