expt2_task1_full

Data Wrangling

data_path <- "/Users/apple/Desktop/JHU/Energy_Data_Analysis/main_expt2_task1_data_raw"
mean_dif <- read.csv("/Users/apple/Desktop/JHU/Energy_Data_Analysis/mean_dif.csv")
file_paths <- list.files(path = data_path, full.names = TRUE)
d_task1 <- tidytable::map_df(file_paths, ~ read.csv(.x) %>% 
              mutate(filename = basename(.x))) 

d_task1$response <- as.numeric(d_task1$response)
Warning: NAs introduced by coercion
d_task1_filtered <- d_task1 |>
  dplyr::filter(task %in% c("energy-compcheck","diff-compcheck","diff-rating")) %>% #subset to relevant trials 
  dplyr::group_by(filename) %>%
  mutate(correct = case_when(
    activity == "att_middle" & response > 48 & response < 52 ~ "true",
    activity == "att_right" & as.numeric(response) == 100 ~ "true",
    activity %in% c("att_middle", "att_right") ~ "false",
    TRUE ~ correct  
  )) %>%
    dplyr::filter(sum(correct == "false",na.rm = TRUE) < 2) #remove 2+ fails in comp+att checks

length(unique(d_task1_filtered$filename)) # n=81
[1] 81
#cleaning up to test trials + energy level
d_task1_clean <- d_task1_filtered %>%
  filter(!task %in% c("energy-compcheck","diff-compcheck") & !activity %in% c("att_right","att_middle")) %>% 
  mutate(energy_level = case_when(
    str_detect(stimulus, "extremely tired") ~ "extremely tired",
    str_detect(stimulus, "extremely energetic") ~ "extremely energetic",
    TRUE ~ NA
  ))

#create pseudo id
d_task1_clean <- d_task1_clean %>%
  group_by(filename) %>%
  mutate(subjectID = sprintf("sub%03d", cur_group_id())) %>%
  ungroup() #add pseudo id

d_task1_clean$subjectID <- as.factor(d_task1_clean$subjectID)
#adding act_type and act_diff (continuous & categorical)
d_task1_labeled <- d_task1_clean %>%
  mutate(act_type = case_when(
    str_detect(activity, "run") | str_detect(activity, "clean") | str_detect(activity, "hike") | str_detect(activity, "jump") | str_detect(activity, "climb") | str_detect(activity, "swim") ~ "physical",
    str_detect(activity, "handwriting") | str_detect(activity, "math") | str_detect(activity, "violin") | str_detect(activity, "homework") | str_detect(activity, "flashcards") | str_detect(activity, "alphabet") ~ "mental",
    TRUE ~ "restorative"))

d_task1_labeled <- d_task1_labeled %>%
  mutate(activity = case_when(
    activity %in% c("do their homework") ~ "do homework",
    activity %in% c("listen to their favorite stories") ~ "listen to favorite stories",
    activity %in% c("watch their favorite show on the couch") ~ "watch favorite show on the couch",
    TRUE ~ activity))

d_task1_merged <- d_task1_labeled |>
  dplyr::left_join(mean_dif, by = "activity")

d_task1_merged$act_mean_diff <- d_task1_merged$act_diff
  
d_task1_merged <- d_task1_merged %>%
  mutate(act_diff_level = case_when(
    str_detect(stimulus, "run") | str_detect(stimulus, "climb") | str_detect(stimulus, "math") | str_detect(stimulus, "homework") ~ "hard",
    str_detect(stimulus, "hike") | str_detect(stimulus, "house") | str_detect(stimulus, "violin") | str_detect(stimulus, "handwriting") ~ "medium",
    str_detect(stimulus, "jump") | str_detect(stimulus, "swim") | str_detect(stimulus, "alphabet") | str_detect(stimulus, "sounding") ~ "easy",
    TRUE ~ NA 
  ))
#Removing outliers
library(olsrr) 
library(influence.ME)

d_task1_phys_ment <- d_task1_merged |>
  filter(act_type=="physical"|act_type=="mental")
  
infl <- influence(lmer(formula = response ~ energy_level + (1 |subjectID), data=d_task1_phys_ment), group = "subjectID")
cooksd <- cooks.distance(infl, sort=TRUE) # this measures how much the model’s fixed-effect estimates change when one subject is dropped

plot(infl, which = "cook",
     cutoff=4/81, sort=TRUE,) # 17 outliers at threshold 4/N 

d_task1_after_exclusion <- d_task1_merged %>%
  filter(!subjectID %in% rownames(cooksd)[cooksd > 4/81])

length(unique(d_task1_after_exclusion$filename)) # n=64 in final sample
[1] 64

Outlier inspection

d_task1_outliers <- d_task1_merged %>%
  filter(subjectID %in% rownames(cooksd)[cooksd > 4/81])

d_task1_outliers$act_type <- factor(d_task1_outliers$act_type, levels = c("physical", "mental", "restorative"))
d_task1_outliers$act_diff_level <- factor(d_task1_outliers$act_diff_level, levels = c("easy", "medium", "hard"))
d_task1_outliers$energy_level <- factor(d_task1_outliers$energy_level)

ggplot(d_task1_outliers,
       aes(x = act_type, y=response, fill=act_diff_level))+ 
  stat_boxplot(geom='errorbar')+
  geom_boxplot() +
  facet_wrap(~energy_level) +
 # stat_summary(fun.y=mean, geom="point", size=1)+
  theme_minimal()+
  scale_fill_brewer(palette="Oranges")+
  labs(title="Outlier Data: Inferred Difficulty Given Energy Level",x="Energy Level",y="Inferred Difficulty",fill="difficulty level")+
  theme(plot.title = element_text(size=15))

The outliers don’t look too problematic, but certainly there’s much more variability in response especially in extremely energetic condition.

Visualization

d_task1_after_exclusion$act_type <- factor(d_task1_after_exclusion$act_type, levels = c("physical", "mental", "restorative"))
d_task1_after_exclusion$act_diff_level <- factor(d_task1_after_exclusion$act_diff_level, levels = c("easy", "medium", "hard"))
d_task1_after_exclusion$energy_level <- factor(d_task1_after_exclusion$energy_level)

ggplot(d_task1_after_exclusion,
       aes(x = act_type, y=response, fill=act_diff_level)) + 
  stat_boxplot(geom='errorbar')+
  geom_boxplot() +
  facet_wrap(~energy_level) +
 # stat_summary(fun.y=mean, geom="point", size=1)+
  theme_minimal()+
  scale_fill_brewer(palette="Oranges")+
  labs(title="Inferred Difficulty Given Energy Level (phys & ment)",x="Energy Level",y="Inferred Difficulty",fill="difficulty level")+
  theme(plot.title = element_text(size=15))

we see an effect of energy level - adults infer things are easier when someone’s energetic than when someone’s tired

also differ by activity type -

  • physical activities are judged as extremely easy when someone’s energetic, and extremely hard when someone’s tired

  • mental activities are judged as easy overall (but less easy than physical activities) when someone’s energetic, with a lot of variability. mental activities are judged as hard overall (but less hard than physical activities) when someone’s tired. There seems to be a sense that energy impacts difficulty/cost of physical activities much more than mental activities.

even though energy has large impact on difficulty judgement, people still differentiate between activities of different difficulty levels -

  • when someone’s energetic, hard physical activities are still judged as less easy than easy/medium physical activities. when someone’s tired, hard mental activities are still judged as more difficult than easy/medium mental activities. This means people make fine-grained difficulty judgments at two energy extremes - being extremely energetic does not make everything equally easy, and being extremely tired does not disable people from carrying out activities and make them find everything equally hard.
restorative_energetic <- d_task1_after_exclusion |>
  filter(act_type=="restorative" & energy_level =="extremely energetic")

restorative_tired <- d_task1_after_exclusion |>
  filter(act_type=="restorative" & energy_level =="extremely tired")

t.test(restorative_tired$response,mu=50,alternative = "two.sided")

    One Sample t-test

data:  restorative_tired$response
t = -2.3695, df = 195, p-value = 0.01879
alternative hypothesis: true mean is not equal to 50
95 percent confidence interval:
 38.95924 48.98974
sample estimates:
mean of x 
 43.97449 
t.test(restorative_energetic$response,mu=50,alternative = "two.sided")

    One Sample t-test

data:  restorative_energetic$response
t = -4.5576, df = 187, p-value = 9.325e-06
alternative hypothesis: true mean is not equal to 50
95 percent confidence interval:
 33.52994 43.48070
sample estimates:
mean of x 
 38.50532 

Are restorative activities always rated easy?

yes, difficulty of restorative activities are rated below 50 (as easy), for both extremely tired and extremely energetic conditions.

Modeling

library(lmerTest)

levels(d_task1_after_exclusion$energy_level)
[1] "extremely energetic" "extremely tired"    
levels(d_task1_after_exclusion$act_diff_level)
[1] "easy"   "medium" "hard"  
levels(d_task1_after_exclusion$act_type)
[1] "physical"    "mental"      "restorative"
d_task1_after_exclusion_physment <- d_task1_after_exclusion |>
  filter(act_type!="restorative")

# Primary H - does difficulty judgement change depending on one's energy level?
model1 <- lmer(data=d_task1_after_exclusion_physment, formula=response ~ energy_level + (1|subjectID))
summary(model1) #Yes
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: response ~ energy_level + (1 | subjectID)
   Data: d_task1_after_exclusion_physment

REML criterion at convergence: 6873.9

Scaled residuals: 
    Min      1Q  Median      3Q     Max 
-4.4378 -0.6588  0.0028  0.4295  3.7684 

Random effects:
 Groups    Name        Variance Std.Dev.
 subjectID (Intercept)  57.22    7.564  
 Residual              420.19   20.499  
Number of obs: 768, groups:  subjectID, 64

Fixed effects:
                            Estimate Std. Error      df t value Pr(>|t|)    
(Intercept)                   30.676      1.444 126.157   21.24   <2e-16 ***
energy_levelextremely tired   61.288      1.518 739.530   40.37   <2e-16 ***
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
            (Intr)
enrgy_lvlxt -0.556

Difficulty judgement of physical and mental activities changes depending on one’s energy level.

# Exploratory Q1 - does difficulty judgment change depending on activity type and/or activity difficulty, on top of energy level? 
model2 <- lmer(data=d_task1_after_exclusion, formula=response ~ energy_level + act_type + act_mean_diff + (1|subjectID))
plot(allEffects(model2))

summary(model2) # Yes
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: response ~ energy_level + act_type + act_mean_diff + (1 | subjectID)
   Data: d_task1_after_exclusion

REML criterion at convergence: 11059

Scaled residuals: 
    Min      1Q  Median      3Q     Max 
-2.9717 -0.6598  0.0809  0.6119  2.9304 

Random effects:
 Groups    Name        Variance Std.Dev.
 subjectID (Intercept)  37.99    6.163  
 Residual              845.77   29.082  
Number of obs: 1152, groups:  subjectID, 64

Fixed effects:
                             Estimate Std. Error        df t value Pr(>|t|)    
(Intercept)                   18.9899     4.8768 1146.9370   3.894 0.000104 ***
energy_levelextremely tired   42.5524     1.7419 1137.2746  24.429  < 2e-16 ***
act_typemental                 4.9192     2.1502 1083.7827   2.288 0.022343 *  
act_typerestorative           -4.7315     3.9377 1083.8065  -1.202 0.229788    
act_mean_diff                  0.3077     0.0691 1083.9389   4.454 9.32e-06 ***
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
            (Intr) enrg_t act_typm act_typr
enrgy_lvlxt -0.149                         
act_typmntl -0.414  0.019                  
act_typrstr -0.895 -0.026  0.443           
act_men_dff -0.919 -0.050  0.215    0.846  

Difficulty judgment changes depending on activity type and activity difficulty, after taking energy level into account. In extremely energetic condition, mental activities are rated 4.9 points higher than physical activities, while restorative activities are rated no different from physical activities. For every 1-unit increase in activity mean difficulty, there is 0.3 unit increase in inferred difficulty.

# Exploratory Q2 - does the effect of energy level on difficulty judgment change depending on activity type, taking into account mean activity difficulty? 
model3 <- lmer(data=d_task1_after_exclusion, formula=response ~ energy_level*act_type + act_mean_diff + (1|subjectID))

plot(allEffects(model3))

summary(model3) 
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: response ~ energy_level * act_type + act_mean_diff + (1 | subjectID)
   Data: d_task1_after_exclusion

REML criterion at convergence: 10744.8

Scaled residuals: 
    Min      1Q  Median      3Q     Max 
-3.5300 -0.6784 -0.0156  0.4896  3.4176 

Random effects:
 Groups    Name        Variance Std.Dev.
 subjectID (Intercept)  46.85    6.844  
 Residual              640.33   25.305  
Number of obs: 1152, groups:  subjectID, 64

Fixed effects:
                                                  Estimate Std. Error
(Intercept)                                        5.22456    4.36444
energy_levelextremely tired                       74.62197    2.63940
act_typemental                                    19.23950    2.69189
act_typerestorative                               28.93745    3.87002
act_mean_diff                                      0.25017    0.06032
energy_levelextremely tired:act_typemental       -26.52629    3.72013
energy_levelextremely tired:act_typerestorative  -69.11517    3.71822
                                                        df t value Pr(>|t|)    
(Intercept)                                     1140.76497   1.197    0.232    
energy_levelextremely tired                     1118.77961  28.272  < 2e-16 ***
act_typemental                                  1102.65352   7.147 1.61e-12 ***
act_typerestorative                             1092.03183   7.477 1.55e-13 ***
act_mean_diff                                   1082.33008   4.147 3.63e-05 ***
energy_levelextremely tired:act_typemental      1118.75308  -7.130 1.79e-12 ***
energy_levelextremely tired:act_typerestorative 1120.54368 -18.588  < 2e-16 ***
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
                           (Intr) enrg_t act_typm act_typr act_m_
enrgy_lvlxt                -0.246                                
act_typmntl                -0.398  0.522                         
act_typrstr                -0.851  0.301  0.424                  
act_men_dff                -0.875 -0.093  0.093    0.721         
enrgy_lvlxtrmlytrd:ct_typm  0.164 -0.709 -0.719   -0.204    0.078
enrgy_lvlxtrmlytrd:ct_typr  0.180 -0.706 -0.369   -0.464    0.059
                           enrgy_lvlxtrmlytrd:ct_typm
enrgy_lvlxt                                          
act_typmntl                                          
act_typrstr                                          
act_men_dff                                          
enrgy_lvlxtrmlytrd:ct_typm                           
enrgy_lvlxtrmlytrd:ct_typr  0.500                    

model 3 results:

energetic tired
physical 5.2 79.8
mental 24.5 72.5
restorative 34.2 39.7
  • When extremely energetic, mental activities are rated 19.2 points harder than physical activities, and restorative activities are rated 29 points harder than physical activities (both p<.001). When extremely tired, mental activities are rated 7.3 points (19.2-26.5) less difficult than physical activities, and restorative activities are rated 40.1 (29-69.1) easier than physical activities (both p<.001).

  • People rated physical activities 74.6 points harder in tired than energetic condition, mental activities 48 points harder in tired than in energetic condition, and restorative activities 5.5 points harder in tired than in energetic condition.

increase in activity difficulty leads to 0.25 points higher inferred difficulty judgement.

# Exploratory Q3 - does the effect of energy level on difficulty judgment change depending on activity type, or difficulty level, or both? 
model4 <- lmer(data=d_task1_after_exclusion, formula=response ~ energy_level*act_type*act_diff_level + (1|subjectID))

plot(allEffects(model4))

summary(model4) 
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: response ~ energy_level * act_type * act_diff_level + (1 | subjectID)
   Data: d_task1_after_exclusion

REML criterion at convergence: 6725.2

Scaled residuals: 
    Min      1Q  Median      3Q     Max 
-4.5098 -0.5396 -0.0493  0.4404  4.7267 

Random effects:
 Groups    Name        Variance Std.Dev.
 subjectID (Intercept)  56.84    7.539  
 Residual              366.84   19.153  
Number of obs: 768, groups:  subjectID, 64

Fixed effects:
                                                                Estimate
(Intercept)                                                       17.628
energy_levelextremely tired                                       78.537
act_typemental                                                    21.536
act_diff_levelmedium                                               1.744
act_diff_levelhard                                                11.504
energy_levelextremely tired:act_typemental                       -32.820
energy_levelextremely tired:act_diff_levelmedium                  -1.700
energy_levelextremely tired:act_diff_levelhard                   -10.798
act_typemental:act_diff_levelmedium                               -5.262
act_typemental:act_diff_levelhard                                 -7.881
energy_levelextremely tired:act_typemental:act_diff_levelmedium    8.783
energy_levelextremely tired:act_typemental:act_diff_levelhard     10.381
                                                                Std. Error
(Intercept)                                                          2.522
energy_levelextremely tired                                          3.501
act_typemental                                                       3.414
act_diff_levelmedium                                                 3.470
act_diff_levelhard                                                   3.657
energy_levelextremely tired:act_typemental                           4.937
energy_levelextremely tired:act_diff_levelmedium                     4.929
energy_levelextremely tired:act_diff_levelhard                       5.017
act_typemental:act_diff_levelmedium                                  4.949
act_typemental:act_diff_levelhard                                    5.015
energy_levelextremely tired:act_typemental:act_diff_levelmedium      6.959
energy_levelextremely tired:act_typemental:act_diff_levelhard        7.020
                                                                     df t value
(Intercept)                                                     591.222   6.991
energy_levelextremely tired                                     732.655  22.431
act_typemental                                                  713.697   6.308
act_diff_levelmedium                                            710.880   0.503
act_diff_levelhard                                              715.623   3.146
energy_levelextremely tired:act_typemental                      730.454  -6.648
energy_levelextremely tired:act_diff_levelmedium                726.116  -0.345
energy_levelextremely tired:act_diff_levelhard                  730.881  -2.152
act_typemental:act_diff_levelmedium                             711.640  -1.063
act_typemental:act_diff_levelhard                               713.659  -1.571
energy_levelextremely tired:act_typemental:act_diff_levelmedium 725.835   1.262
energy_levelextremely tired:act_typemental:act_diff_levelhard   728.312   1.479
                                                                Pr(>|t|)    
(Intercept)                                                     7.42e-12 ***
energy_levelextremely tired                                      < 2e-16 ***
act_typemental                                                  4.96e-10 ***
act_diff_levelmedium                                             0.61541    
act_diff_levelhard                                               0.00172 ** 
energy_levelextremely tired:act_typemental                      5.81e-11 ***
energy_levelextremely tired:act_diff_levelmedium                 0.73033    
energy_levelextremely tired:act_diff_levelhard                   0.03171 *  
act_typemental:act_diff_levelmedium                              0.28803    
act_typemental:act_diff_levelhard                                0.11652    
energy_levelextremely tired:act_typemental:act_diff_levelmedium  0.20736    
energy_levelextremely tired:act_typemental:act_diff_levelhard    0.13966    
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
                                          (Intr) enrg_t act_ty act_dff_lvlm
enrgy_lvlxt                               -0.640                           
act_typmntl                               -0.635  0.471                    
act_dff_lvlm                              -0.625  0.465  0.462             
act_dff_lvlh                              -0.595  0.443  0.440  0.431      
enrgy_trd:_                                0.453 -0.708 -0.712 -0.330      
enrgy_lvlxtrmlytrd:ct_dff_lvlm             0.454 -0.710 -0.336 -0.721      
enrgy_lvlxtrmlytrd:ct_dff_lvlh             0.448 -0.700 -0.332 -0.324      
act_typmntl:ct_dff_lvlm                    0.435 -0.320 -0.690 -0.698      
act_typmntl:ct_dff_lvlh                    0.433 -0.322 -0.681 -0.313      
enrgy_lvlxtrmlytrd:ct_typmntl:ct_dff_lvlm -0.317  0.495  0.505  0.507      
enrgy_lvlxtrmlytrd:ct_typmntl:ct_dff_lvlh -0.319  0.499  0.500  0.231      
                                          act_dff_lvlh en_t:_
enrgy_lvlxt                                                  
act_typmntl                                                  
act_dff_lvlm                                                 
act_dff_lvlh                                                 
enrgy_trd:_                               -0.315             
enrgy_lvlxtrmlytrd:ct_dff_lvlm            -0.313        0.504
enrgy_lvlxtrmlytrd:ct_dff_lvlh            -0.748        0.498
act_typmntl:ct_dff_lvlm                   -0.300        0.491
act_typmntl:ct_dff_lvlh                   -0.729        0.485
enrgy_lvlxtrmlytrd:ct_typmntl:ct_dff_lvlm  0.219       -0.709
enrgy_lvlxtrmlytrd:ct_typmntl:ct_dff_lvlh  0.534       -0.703
                                          enrgy_lvlxtrmlytrd:ct_dff_lvlm
enrgy_lvlxt                                                             
act_typmntl                                                             
act_dff_lvlm                                                            
act_dff_lvlh                                                            
enrgy_trd:_                                                             
enrgy_lvlxtrmlytrd:ct_dff_lvlm                                          
enrgy_lvlxtrmlytrd:ct_dff_lvlh             0.495                        
act_typmntl:ct_dff_lvlm                    0.501                        
act_typmntl:ct_dff_lvlh                    0.227                        
enrgy_lvlxtrmlytrd:ct_typmntl:ct_dff_lvlm -0.703                        
enrgy_lvlxtrmlytrd:ct_typmntl:ct_dff_lvlh -0.353                        
                                          enrgy_lvlxtrmlytrd:ct_dff_lvlh
enrgy_lvlxt                                                             
act_typmntl                                                             
act_dff_lvlm                                                            
act_dff_lvlh                                                            
enrgy_trd:_                                                             
enrgy_lvlxtrmlytrd:ct_dff_lvlm                                          
enrgy_lvlxtrmlytrd:ct_dff_lvlh                                          
act_typmntl:ct_dff_lvlm                    0.224                        
act_typmntl:ct_dff_lvlh                    0.545                        
enrgy_lvlxtrmlytrd:ct_typmntl:ct_dff_lvlm -0.347                        
enrgy_lvlxtrmlytrd:ct_typmntl:ct_dff_lvlh -0.715                        
                                          act_typmntl:ct_dff_lvlm
enrgy_lvlxt                                                      
act_typmntl                                                      
act_dff_lvlm                                                     
act_dff_lvlh                                                     
enrgy_trd:_                                                      
enrgy_lvlxtrmlytrd:ct_dff_lvlm                                   
enrgy_lvlxtrmlytrd:ct_dff_lvlh                                   
act_typmntl:ct_dff_lvlm                                          
act_typmntl:ct_dff_lvlh                    0.468                 
enrgy_lvlxtrmlytrd:ct_typmntl:ct_dff_lvlm -0.728                 
enrgy_lvlxtrmlytrd:ct_typmntl:ct_dff_lvlh -0.343                 
                                          act_typmntl:ct_dff_lvlh
enrgy_lvlxt                                                      
act_typmntl                                                      
act_dff_lvlm                                                     
act_dff_lvlh                                                     
enrgy_trd:_                                                      
enrgy_lvlxtrmlytrd:ct_dff_lvlm                                   
enrgy_lvlxtrmlytrd:ct_dff_lvlh                                   
act_typmntl:ct_dff_lvlm                                          
act_typmntl:ct_dff_lvlh                                          
enrgy_lvlxtrmlytrd:ct_typmntl:ct_dff_lvlm -0.342                 
enrgy_lvlxtrmlytrd:ct_typmntl:ct_dff_lvlh -0.732                 
                                          enrgy_lvlxtrmlytrd:ct_typmntl:ct_dff_lvlm
enrgy_lvlxt                                                                        
act_typmntl                                                                        
act_dff_lvlm                                                                       
act_dff_lvlh                                                                       
enrgy_trd:_                                                                        
enrgy_lvlxtrmlytrd:ct_dff_lvlm                                                     
enrgy_lvlxtrmlytrd:ct_dff_lvlh                                                     
act_typmntl:ct_dff_lvlm                                                            
act_typmntl:ct_dff_lvlh                                                            
enrgy_lvlxtrmlytrd:ct_typmntl:ct_dff_lvlm                                          
enrgy_lvlxtrmlytrd:ct_typmntl:ct_dff_lvlh  0.495                                   

In extremely tired condition, mental activities are rated as 32.8 points less difficult than physical activities, hard activities are rated as 10.8 points less difficult than easy activities??