Reading text Data into R

This multiple choice question set relates to the introductory R lesson on data as well as the supplementary lesson on data reading.

Question 1

Can R read data from file having of the following forms listed below?

Pick one of these answers:

• several columns of just numbers, or just text
• several columns of equal length where each column can have just numbers and text
• several columns of equal length where numbers and text can be mixed in each column
• all of the above

Question 2

Should you choose the stringsAsFactors=FALSE option when reading data?

Pick one of these answers:

• no, R already decides heuristically what to do
• no, factors are very helpful for modeling functions and summaries
• yes, characters are easier to alter, and can be converted to factor anyway
• yes, and it is also a good default to set in options()

Question 2 – Discussion

This is a somewhat challenging topic, and question two extends from question one. The possible distractions are

1. this is intentionally misleading; R does indeed apply heuristics when reading a file to determine data types, column width etc – but it does not help here as the (old) default of factors comes from a time when that saved precious memory as opposed to repeating strings (which are now hashed internally and handled efficiently too)
2. this is a valid answers, but useful mostly for advanced users / some contexts
3. this is also a valid answer, and possibly the preferred one
4. this is generally considered bad style as the script then becomes less portable as its behaviour is tied to a (local, machine-only) setting of a global state variable