Multiple Responses/Dichotomies - Multiple Dichotomies

Suppose in the Multiple Response Variables example we were only interested in Coke, Pepsi, and Sprite. As pointed out earlier, one way to code the data in that case would be as follows:

 

COKE

PEPSI

SPRITE

....

case 1

 

1

 

 

case 2

1

1

 

 

case 3

....

 

1

 

....

 

....

...

 

In other words, one variable was created for each soft drink, then a value of 1 was entered into the respective variable whenever the respective drink was mentioned by the respective respondent. Note that each variable represents a dichotomy; that is, only "1s" and "not 1s" are allowed (we could have entered 1s and 0s, but to save typing we can also simply leave the 0s blank or missing). When tabulating these variables, we would like to obtain a summary table very similar to the one shown earlier for multiple response variables; that is, we would like to compute the number and percent of respondents (and responses) for each soft drink. In a sense, we "compact" the three variables Coke, Pepsi, and Sprite into a single variable (Soft Drink) consisting of multiple dichotomies.