title: Recognizing 'select all that apply' answers as being separate in R
body: <p>I'm working with a dataframe, from a survey I took (n=108). One of the questions (columns) contain four possible answers- another, 10. Here is my issue: when plotting either of these columns, it plots each level. The four-answer column is considered a factor with 13 levels and the 10-answer, a factor with 22 levels. Each time someone chose more than one answer, it counts as a separate level (i.e. <code>"A,B"</code>, <code>"A,B,C"</code>, etc.) My question is, how do I go about representing how many respondents chose <code>"A"</code> or <code>"B"</code> or a combination of <code>"A"</code> and <code>"B"</code> but not necessarily/only <code>"A,B"</code>, regardless of what other choices the made, if any.</p>
  
  <p>I wish to plot these items correctly, as well as analyze the data by, say, how many <code>Female</code> respondents chose <code>"A"</code> versus how many <code>Male</code> respondents, and so on.</p>
  
  <p>My issues: </p>
  
  <p>1) <code>plot(data$letter)</code> plots 13 different bars whereas <code>letter</code> is a question with only 4 possible answers, select all that apply.</p>
  
  <p>2) I can't show through analysis how many chose <code>"A"</code> if they also happened to choose another answer, because <code>"A","C"</code> isn't equivalent to <code>"A"</code>.</p>
  
  <p>Solutions I'm searching for: </p>
  
  <p>1) When <code>plot(data$letter)</code>, I want only four bars showing how many times each letter was chosen.</p>
  
  <p>2) I need to work with all values of <code>"A"</code> in analysis, even if the respondent selected more than just <code>"A"</code></p>
  
  <p>Thank you!</p>
  
  <p>Also, <a href="https://stackoverflow.com/questions/27489277/how-to-clean-and-re-code-check-all-that-apply-responses-in-r-survey-data">How to clean and re-code check-all-that-apply responses in R survey data?</a> is a question I found before posting that explains it in totality, but the code is fairly advanced at my level of experience with R.</p>