title: R: read.csv importing the letter i as NA
body: <p>Pretty simple question (I think). I'm trying to import a .csv file into R, from an experiment in which people respond by either pushing the "e" or the "i" key. In testing it, I responded only in with the "i" key, so the response variable in the data set is basically a list of "i"s (without the quotation marks). When I try and import the data into R:</p>
  
  <pre><code>noload=read.csv("~/Desktop/eprime check no load.csv", na.strings = "")
  </code></pre>
  
  <p>the response variable comes out all NAs. When I try it with all "e"s, or a mixture of "e" and "i", it works fine. </p>
  
  <p>What is is about the letter i that makes R treat it as NA (n.b. it does this even without the <code>na.strings = ""</code> part)?</p>
  
  <p>Thanks in advance for any help.</p>