This function prints out a summary of the amount of "overlap" across
attributes within the choice questions. For example, for each attribute, the
count under "1" is the number of choice questions in which the same level
was shown across all alternatives for that attribute (because there was only
one level shown). Likewise, the count under "2" is the number of choice
questions in which only two unique levels of that attribute were shown, and
so on.
cbc_overlap(design)A data frame of a survey design.
Prints the counts of the number of choice questions that contain the unique number of levels for each attribute.
library(cbcTools)
# A simple conjoint experiment about apples
# Generate all possible profiles
profiles <- cbc_profiles(
price = c(1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5),
freshness = c("Excellent", "Average", "Poor"),
type = c("Fuji", "Gala", "Honeycrisp")
)
# Make a randomized survey design
design <- cbc_design(
profiles = profiles,
n_resp = 300, # Number of respondents
n_alts = 3, # Number of alternatives per question
n_q = 6 # Number of questions per respondent
)
# Inspect the design balance
cbc_balance(design)
#> =====================================
#> Individual attribute level counts
#>
#> price:
#>
#> 1 1.5 2 2.5 3 3.5 4 4.5 5
#> 613 633 607 572 567 598 612 607 591
#>
#> freshness:
#>
#> Excellent Average Poor
#> 1826 1802 1772
#>
#> type:
#>
#> Fuji Gala Honeycrisp
#> 1825 1777 1798
#>
#> =====================================
#> Pairwise attribute level counts
#>
#> price x freshness:
#>
#> Excellent Average Poor
#> NA 1826 1802 1772
#> 1 613 203 220 190
#> 1.5 633 219 185 229
#> 2 607 207 229 171
#> 2.5 572 200 211 161
#> 3 567 193 184 190
#> 3.5 598 193 197 208
#> 4 612 211 190 211
#> 4.5 607 189 205 213
#> 5 591 211 181 199
#>
#> price x type:
#>
#> Fuji Gala Honeycrisp
#> NA 1825 1777 1798
#> 1 613 233 191 189
#> 1.5 633 207 218 208
#> 2 607 197 192 218
#> 2.5 572 199 188 185
#> 3 567 194 199 174
#> 3.5 598 213 179 206
#> 4 612 198 200 214
#> 4.5 607 189 214 204
#> 5 591 195 196 200
#>
#> freshness x type:
#>
#> Fuji Gala Honeycrisp
#> NA 1825 1777 1798
#> Excellent 1826 627 573 626
#> Average 1802 596 614 592
#> Poor 1772 602 590 580
#>
# Inspect the design overlap
cbc_overlap(design)
#> ==============================
#> Counts of attribute overlap:
#> (# of questions with N unique levels)
#>
#> price:
#>
#> 1 2 3
#> 12 483 1305
#>
#> freshness:
#>
#> 1 2 3
#> 188 1200 412
#>
#> type:
#>
#> 1 2 3
#> 182 1194 424
#>