Open mmb951 opened 6 years ago
Hi,
I agree that this feature would be really useful. In the meantime, I have a little work-around that I'm pretty confidence isn't statistically bad. The idea is to trick eyetrackingR by creating a chance-level dataset to compare the actual data to:
response_time <- response_window_clean %>%
mutate(Chance = F) %>% # This is the actual data, not the chance level
make_time_sequence_data(time_bin_size = 100,
aois = "YourAOI",
predictor_columns="Chance",
summarize_by = "ParticipantName")
# Create the chance-level data
response_time.chance <- response_time %>%
mutate(Chance = T, # This is the chance data
Participant = paste0("Chance", Participant),
# This is so eyetrackingR is okay with within_part = F
Prop = .5) # Change with your actual chance level
# If you use a DV other than Prop in your test, just change this DV instead
# Merging the data and chance datasets together
response_window.chance_test <- rbind(response_window,
response_window.chance) %>%
mutate_at("Chance", parse_factor, levels = NULL) # Just in case
After that, you can just run the analysis using Chance
as a predictor column:
# Determine threshold based on alpha = .05 two-tailed
num_sub = length(unique((response_window.chance_test$ParticipantName)))
threshold_t = qt(p = 1 - .05/2,
df = num_sub-1)
# Determine clusters
df_timeclust <- response_window.chance_test %>%
make_time_cluster_data(predictor_column = "Chance",
aoi = "YourAOI",
test = "t.test",
threshold = threshold_t)
# Run analysis
clust_analysis <- analyze_time_clusters(df_timeclust,
within_subj = F,
parallel = T)
@respatte Great, I will try that. Thanks a lot for your help
hi! this is great, thanks @respatte . My issue is that the cluster analysis does not provide a t or p statistic as far as I can tell. The function analyze_time_bins produces these but I don't think your method will work with analyze_time_bins. Any recommendations?
@sambfloyd I didn't test it but I don't see why this workaround wouldn't work with analyze_time_bins
, have you tried it?
I'm guessing what you want is a t-statistic for each time bin, whether it reaches the defined threshold or not? In that case you would need to use analyse_time_bins
indeed, but analyze_time_clusters
does give you the summed t statistic for each cluster.
@respatte sorry for not updating, I did exactly that and forgot to post -- it works great.
The only minor issue I have (with both clusters and bins) is the mutate_at line of code- it runs but it seems to recode the Chance variable weirdly-- when I look at the levels it says character(0) instead of NULL (which does work for the analysis). But I just run it without that since chance is comes out as having NULL levels before that line.
Hi
First of all, thanks for the useful EytrackingR website. I would like to run a 'time cluster'-type analysis using a 1-sample t-test to test when the bias to a target AOI significantly exceeds chance (in our experiment .25; with time as a continuous variable in 50ms bins). Is this possible in the current functions, please?
Many thanks Mahsa