--- title: "Mixed ANOVA Analysis for Domain Means" author: "Irina" date: "`r Sys.Date()`" output: html_document: toc: true toc_float: true code_folding: hide theme: flatly highlight: tango fig_width: 10 fig_height: 6 --- ```{r setup, include=FALSE} knitr::opts_chunk$set(echo = FALSE, warning = FALSE, message = FALSE) ``` # Introduction This analysis examines domain-level differences in mean scores across time periods using a mixed ANOVA design. The analysis focuses on four domains (Preferences, Personality, Values, Life) across two time periods (Past, Future) with a between-subjects factor (TEMPORAL_DO). # Data Preparation and Setup ```{r libraries} library(tidyverse) library(ez) library(car) library(nortest) # For normality tests library(emmeans) # For post-hoc comparisons library(purrr) # For map functions library(effsize) # For Cohen's d calculations library(ggplot2) # For plotting options(scipen = 999) options(contrasts = c("contr.sum", "contr.poly")) setwd("C:/Users/irina/Documents/DND/EOHI/eohi1") ``` ```{r data-loading} # Read the data data <- read.csv("exp1.csv") required_vars <- c("NPast_mean_pref", "NPast_mean_pers", "NPast_mean_val", "NPast_mean_life", "NFut_mean_pref", "NFut_mean_pers", "NFut_mean_val", "NFut_mean_life") # Define domain mapping domain_mapping <- data.frame( variable = c("NPast_mean_pref", "NPast_mean_pers", "NPast_mean_val", "NPast_mean_life", "NFut_mean_pref", "NFut_mean_pers", "NFut_mean_val", "NFut_mean_life"), time = c(rep("Past", 4), rep("Future", 4)), domain = rep(c("Preferences", "Personality", "Values", "Life"), 2), stringsAsFactors = FALSE ) ``` ```{r data-reshaping} long_data <- data %>% select(pID, ResponseId, TEMPORAL_DO, all_of(required_vars)) %>% pivot_longer( cols = all_of(required_vars), names_to = "variable", values_to = "MEAN_DIFFERENCE" ) %>% left_join(domain_mapping, by = "variable") %>% # Convert to factors with proper levels (note: columns are 'time' and 'domain' from mapping) mutate( TIME = factor(time, levels = c("Past", "Future")), DOMAIN = factor(domain, levels = c("Preferences", "Personality", "Values", "Life")), pID = as.factor(pID), TEMPORAL_DO = as.factor(TEMPORAL_DO) ) %>% # Select final columns and remove any rows with missing values select(pID, ResponseId, TEMPORAL_DO, TIME, DOMAIN, MEAN_DIFFERENCE) %>% filter(!is.na(MEAN_DIFFERENCE)) # Create clean dataset for analysis (fixing the reference issue) long_data_clean <- long_data ``` # Descriptive Statistics ## Overall Descriptive Statistics by TIME and DOMAIN ```{r descriptive-stats} desc_stats <- long_data %>% group_by(TIME, DOMAIN) %>% summarise( n = n(), mean = round(mean(MEAN_DIFFERENCE, na.rm = TRUE), 5), variance = round(var(MEAN_DIFFERENCE, na.rm = TRUE), 5), sd = round(sd(MEAN_DIFFERENCE, na.rm = TRUE), 5), median = round(median(MEAN_DIFFERENCE, na.rm = TRUE), 5), q1 = round(quantile(MEAN_DIFFERENCE, 0.25, na.rm = TRUE), 5), q3 = round(quantile(MEAN_DIFFERENCE, 0.75, na.rm = TRUE), 5), min = round(min(MEAN_DIFFERENCE, na.rm = TRUE), 5), max = round(max(MEAN_DIFFERENCE, na.rm = TRUE), 5), .groups = 'drop' ) print(desc_stats) ``` ## Descriptive Statistics by Between-Subjects Factors ```{r descriptive-stats-temporal} desc_stats_by_temporal <- long_data %>% group_by(TEMPORAL_DO, TIME, DOMAIN) %>% summarise( n = n(), mean = round(mean(MEAN_DIFFERENCE, na.rm = TRUE), 5), variance = round(var(MEAN_DIFFERENCE, na.rm = TRUE), 5), sd = round(sd(MEAN_DIFFERENCE, na.rm = TRUE), 5), .groups = 'drop' ) print(desc_stats_by_temporal) ``` # Assumption Testing ## Missing Values Check ```{r missing-values} missing_summary <- long_data %>% group_by(TIME, DOMAIN) %>% summarise( n_total = n(), n_missing = sum(is.na(MEAN_DIFFERENCE)), pct_missing = round(100 * n_missing / n_total, 2), .groups = 'drop' ) print(missing_summary) ``` ## Outlier Detection ```{r outlier-detection} outlier_summary <- long_data_clean %>% group_by(TIME, DOMAIN) %>% summarise( n = n(), mean = mean(MEAN_DIFFERENCE), sd = sd(MEAN_DIFFERENCE), q1 = quantile(MEAN_DIFFERENCE, 0.25), median = median(MEAN_DIFFERENCE), q3 = quantile(MEAN_DIFFERENCE, 0.75), iqr = q3 - q1, lower_bound = q1 - 1.5 * iqr, upper_bound = q3 + 1.5 * iqr, n_outliers = sum(MEAN_DIFFERENCE < lower_bound | MEAN_DIFFERENCE > upper_bound), .groups = 'drop' ) print(outlier_summary) ``` ## Anderson-Darling Normality Test ```{r normality-test} normality_results <- long_data_clean %>% group_by(TIME, DOMAIN) %>% summarise( n = n(), ad_statistic = ad.test(.data$MEAN_DIFFERENCE)$statistic, ad_p_value = ad.test(.data$MEAN_DIFFERENCE)$p.value, .groups = 'drop' ) print(normality_results) ``` ## Homogeneity of Variance (Levene's Test) ### Test homogeneity across TIME within each DOMAIN ```{r homogeneity-time} homogeneity_time <- long_data_clean %>% group_by(DOMAIN) %>% summarise( levene_F = leveneTest(MEAN_DIFFERENCE ~ TIME)$`F value`[1], levene_p = leveneTest(MEAN_DIFFERENCE ~ TIME)$`Pr(>F)`[1], .groups = 'drop' ) print(homogeneity_time) ``` ### Test homogeneity across DOMAIN within each TIME ```{r homogeneity-domain} homogeneity_domain <- long_data_clean %>% group_by(TIME) %>% summarise( levene_F = leveneTest(MEAN_DIFFERENCE ~ DOMAIN)$`F value`[1], levene_p = leveneTest(MEAN_DIFFERENCE ~ DOMAIN)$`Pr(>F)`[1], .groups = 'drop' ) print(homogeneity_domain) ``` ## Hartley's F-Max Test with Bootstrap Critical Values ```{r hartley-function} # Function to calculate Hartley's F-max ratio calculate_hartley_ratio <- function(variances) { max(variances, na.rm = TRUE) / min(variances, na.rm = TRUE) } # More efficient bootstrap function for Hartley's F-max test bootstrap_hartley_critical <- function(data, group_var, response_var, n_iter = 1000) { # Get unique groups and their sample sizes groups <- unique(data[[group_var]]) # Calculate observed variances for each group observed_vars <- data %>% dplyr::group_by(!!rlang::sym(group_var)) %>% dplyr::summarise(var = var(!!rlang::sym(response_var), na.rm = TRUE), .groups = 'drop') %>% dplyr::pull(var) # Handle invalid variances if(any(observed_vars <= 0 | is.na(observed_vars))) { observed_vars[observed_vars <= 0 | is.na(observed_vars)] <- 1e-10 } # Calculate observed F-max ratio observed_ratio <- max(observed_vars) / min(observed_vars) # Pre-allocate storage for bootstrap ratios bootstrap_ratios <- numeric(n_iter) # Get group data once group_data_list <- map(groups, ~ { group_data <- data[data[[group_var]] == .x, response_var] group_data[!is.na(group_data)] }) # Bootstrap with pre-allocated storage for(i in 1:n_iter) { # Bootstrap sample from each group independently sample_vars <- map_dbl(group_data_list, ~ { bootstrap_sample <- sample(.x, size = length(.x), replace = TRUE) var(bootstrap_sample, na.rm = TRUE) }) bootstrap_ratios[i] <- max(sample_vars) / min(sample_vars) } # Remove invalid ratios valid_ratios <- bootstrap_ratios[is.finite(bootstrap_ratios) & !is.na(bootstrap_ratios)] if(length(valid_ratios) == 0) { stop("No valid bootstrap ratios generated") } # Calculate critical value (95th percentile) critical_95 <- quantile(valid_ratios, 0.95, na.rm = TRUE) # Return only essential information return(list( observed_ratio = observed_ratio, critical_95 = critical_95, n_valid_iterations = length(valid_ratios) )) } ``` ```{r hartley-results} # For mixed ANOVA: Test homogeneity across BETWEEN-SUBJECTS factor (TEMPORAL_DO) # within each combination of within-subjects factors (TIME × DOMAIN) print(unique(long_data_clean$TEMPORAL_DO)) print(table(long_data_clean$TEMPORAL_DO)) observed_temporal_ratios <- long_data_clean %>% group_by(TIME, DOMAIN) %>% summarise( # Calculate variances for each TEMPORAL_DO level within this TIME × DOMAIN combination past_var = var(MEAN_DIFFERENCE[TEMPORAL_DO == "01PAST"], na.rm = TRUE), fut_var = var(MEAN_DIFFERENCE[TEMPORAL_DO == "02FUT"], na.rm = TRUE), # Calculate F-max ratio f_max_ratio = max(past_var, fut_var) / min(past_var, fut_var), .groups = 'drop' ) %>% select(TIME, DOMAIN, past_var, fut_var, f_max_ratio) print(observed_temporal_ratios) # Hartley's F-max test across TEMPORAL_DO within each TIME × DOMAIN combination set.seed(123) # For reproducibility hartley_temporal_results <- long_data_clean %>% group_by(TIME, DOMAIN) %>% summarise( hartley_result = list(bootstrap_hartley_critical(pick(TEMPORAL_DO, MEAN_DIFFERENCE), "TEMPORAL_DO", "MEAN_DIFFERENCE")), .groups = 'drop' ) %>% mutate( observed_ratio = map_dbl(hartley_result, ~ .x$observed_ratio), critical_95 = map_dbl(hartley_result, ~ .x$critical_95), significant = observed_ratio > critical_95 ) %>% select(TIME, DOMAIN, observed_ratio, critical_95, significant) print(hartley_temporal_results) ``` # Mixed ANOVA Analysis ## Design Balance Check ```{r design-check} # Check for complete cases complete_cases <- sum(complete.cases(long_data_clean)) print(complete_cases) # Check if design is balanced design_balance <- table(long_data_clean$pID, long_data_clean$TIME, long_data_clean$DOMAIN) if(all(design_balance %in% c(0, 1))) { print("Design is balanced: each participant has data for all TIME × DOMAIN combinations") } else { print("Warning: Design is unbalanced") print(summary(as.vector(design_balance))) } ``` ## Mixed ANOVA with Sphericity Corrections ```{r mixed-anova} # Mixed ANOVA using ezANOVA with automatic sphericity corrections # Between-subjects: TEMPORAL_DO (2 levels: 01PAST, 02FUT) # Within-subjects: TIME (2 levels: Past, Future) × DOMAIN (4 levels: Preferences, Personality, Values, Life) mixed_anova_model <- ezANOVA(data = long_data_clean, dv = MEAN_DIFFERENCE, wid = pID, between = TEMPORAL_DO, within = .(TIME, DOMAIN), type = 3, detailed = TRUE) anova_output <- mixed_anova_model$ANOVA rownames(anova_output) <- NULL # Reset row numbers to be sequential print(anova_output) ``` ## Mauchly's Test for Sphericity ```{r mauchly-test} print(mixed_anova_model$Mauchly) ``` ## Sphericity-Corrected Results ```{r sphericity-corrections} # Show sphericity-corrected results (Greenhouse-Geisser and Huynh-Feldt) if(!is.null(mixed_anova_model$`Sphericity Corrections`)) { print(mixed_anova_model$`Sphericity Corrections`) # Extract and display corrected degrees of freedom sphericity_corr <- mixed_anova_model$`Sphericity Corrections` anova_table <- mixed_anova_model$ANOVA corrected_df <- data.frame( Effect = sphericity_corr$Effect, Original_DFn = anova_table$DFn[match(sphericity_corr$Effect, anova_table$Effect)], Original_DFd = anova_table$DFd[match(sphericity_corr$Effect, anova_table$Effect)], GG_DFn = anova_table$DFn[match(sphericity_corr$Effect, anova_table$Effect)] * sphericity_corr$GGe, GG_DFd = anova_table$DFd[match(sphericity_corr$Effect, anova_table$Effect)] * sphericity_corr$GGe, HF_DFn = anova_table$DFn[match(sphericity_corr$Effect, anova_table$Effect)] * sphericity_corr$HFe, HF_DFd = anova_table$DFd[match(sphericity_corr$Effect, anova_table$Effect)] * sphericity_corr$HFe, GG_epsilon = sphericity_corr$GGe, HF_epsilon = sphericity_corr$HFe ) print(corrected_df) # Between-subjects effects (no sphericity corrections needed) between_effects <- c("TEMPORAL_DO") for(effect in between_effects) { if(effect %in% anova_table$Effect) { f_value <- anova_table$F[anova_table$Effect == effect] dfn <- anova_table$DFn[anova_table$Effect == effect] dfd <- anova_table$DFd[anova_table$Effect == effect] p_value <- anova_table$p[anova_table$Effect == effect] cat(sprintf("%s: F(%d, %d) = %.3f, p = %.6f\n", effect, dfn, dfd, f_value, p_value)) } } # Within-subjects effects (sphericity corrections where applicable) # TIME main effect (2 levels, sphericity automatically satisfied) if("TIME" %in% anova_table$Effect) { f_value <- anova_table$F[anova_table$Effect == "TIME"] dfn <- anova_table$DFn[anova_table$Effect == "TIME"] dfd <- anova_table$DFd[anova_table$Effect == "TIME"] p_value <- anova_table$p[anova_table$Effect == "TIME"] cat(sprintf("TIME: F(%d, %d) = %.3f, p = %.6f (2 levels, sphericity satisfied)\n", dfn, dfd, f_value, p_value)) } # DOMAIN main effect (4 levels, needs sphericity correction) if("DOMAIN" %in% anova_table$Effect) { f_value <- anova_table$F[anova_table$Effect == "DOMAIN"] dfn <- anova_table$DFn[anova_table$Effect == "DOMAIN"] dfd <- anova_table$DFd[anova_table$Effect == "DOMAIN"] p_value <- anova_table$p[anova_table$Effect == "DOMAIN"] cat(sprintf("DOMAIN: F(%d, %d) = %.3f, p = %.6f\n", dfn, dfd, f_value, p_value)) } # Interactions with sphericity corrections for(i in seq_len(nrow(corrected_df))) { effect <- corrected_df$Effect[i] f_value <- anova_table$F[match(effect, anova_table$Effect)] cat(sprintf("\n%s:\n", effect)) cat(sprintf(" Original: F(%d, %d) = %.3f\n", corrected_df$Original_DFn[i], corrected_df$Original_DFd[i], f_value)) cat(sprintf(" GG-corrected: F(%.2f, %.2f) = %.3f, p = %.6f\n", corrected_df$GG_DFn[i], corrected_df$GG_DFd[i], f_value, sphericity_corr$`p[GG]`[i])) cat(sprintf(" HF-corrected: F(%.2f, %.2f) = %.3f, p = %.6f\n", corrected_df$HF_DFn[i], corrected_df$HF_DFd[i], f_value, sphericity_corr$`p[HF]`[i])) } } else { print("\nNote: Sphericity corrections not needed (sphericity assumption met)") } ``` # Effect Sizes (Cohen's d) ## Main Effects ```{r cohens-d-main} # Create aov model for emmeans aov_model <- aov(MEAN_DIFFERENCE ~ TEMPORAL_DO * TIME * DOMAIN + Error(pID/(TIME * DOMAIN)), data = long_data_clean) # Main Effect of TIME time_emmeans <- emmeans(aov_model, ~ TIME) print(time_emmeans) time_main_contrast <- pairs(time_emmeans, adjust = "Bonferroni") time_main_df <- as.data.frame(time_main_contrast) print(time_main_df) # Calculate Cohen's d for TIME main effect if(nrow(time_main_df) > 0) { cat("\nCohen's d for TIME main effect:\n") time_past_data <- long_data_clean$MEAN_DIFFERENCE[long_data_clean$TIME == "Past"] time_future_data <- long_data_clean$MEAN_DIFFERENCE[long_data_clean$TIME == "Future"] time_cohens_d <- cohen.d(time_past_data, time_future_data) cat(sprintf("Past vs Future: n1 = %d, n2 = %d\n", length(time_past_data), length(time_future_data))) cat(sprintf("Cohen's d: %.5f\n", time_cohens_d$estimate)) cat(sprintf("Effect size interpretation: %s\n", time_cohens_d$magnitude)) cat(sprintf("p-value: %.5f\n", time_main_df$p.value[1])) } ``` ```{r cohens-d-domain} # Main Effect of DOMAIN (significant: p < 0.001) domain_emmeans <- emmeans(aov_model, ~ DOMAIN) print(domain_emmeans) domain_main_contrast <- pairs(domain_emmeans, adjust = "bonferroni") domain_main_df <- as.data.frame(domain_main_contrast) print(domain_main_df) # Calculate Cohen's d for significant DOMAIN contrasts significant_domain <- domain_main_df[domain_main_df$p.value < 0.05, ] if(nrow(significant_domain) > 0) { cat("\nCohen's d for significant DOMAIN contrasts:\n") for(i in seq_len(nrow(significant_domain))) { contrast_name <- as.character(significant_domain$contrast[i]) contrast_parts <- strsplit(contrast_name, " - ")[[1]] if(length(contrast_parts) == 2) { level1 <- trimws(contrast_parts[1]) level2 <- trimws(contrast_parts[2]) data1 <- long_data_clean$MEAN_DIFFERENCE[long_data_clean$DOMAIN == level1] data2 <- long_data_clean$MEAN_DIFFERENCE[long_data_clean$DOMAIN == level2] if(length(data1) > 0 && length(data2) > 0) { domain_cohens_d <- cohen.d(data1, data2) cat(sprintf("Comparison: %s\n", contrast_name)) cat(sprintf(" n1 = %d, n2 = %d\n", length(data1), length(data2))) cat(sprintf(" Cohen's d: %.5f\n", domain_cohens_d$estimate)) cat(sprintf(" Effect size interpretation: %s\n", domain_cohens_d$magnitude)) cat(sprintf(" p-value: %.5f\n", significant_domain$p.value[i])) cat("\n") } } } } ```