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Re: st: converting multiple choice (string) response options to numeric values
From
Katherine Picho <[email protected]>
To
[email protected]
Subject
Re: st: converting multiple choice (string) response options to numeric values
Date
Fri, 7 Feb 2014 08:32:06 -0500
Will do!
The sketch you provided to the list worked well! I also have
downloaded multencode...cant wait to try all of these!
On Fri, Feb 7, 2014 at 8:30 AM, Nick Cox <[email protected]> wrote:
> See also on a different variant of the same problem
>
> SJ-11-2 dm0057 . . . . . . . . . Stata tip 99: Taking extra care with encode
> . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C. Schechter
> Q2/11 SJ 11(2):321--322 (no commands)
> tip on safely using encode across datasets
>
> Nick
> [email protected]
>
>
> On 7 February 2014 11:30, Nick Cox <[email protected]> wrote:
>> This is quite a common problem, and it's easy to get bitten.
>>
>> label def mylabels 1 "A" 2 "B" 3 "C" 4 "D" 5 "E"
>>
>> foreach v of var <varlist> {
>> encode `v', gen(n_`v') label(mylabels)
>> }
>>
>> is a sketch of how to do it. You must replace <varlist> by an actual varlist.
>>
>> Alternatively, as said, look at -multencode- (SSC).
>>
>> Nick
>> [email protected]
>>
>>
>> On 7 February 2014 09:22, Nick Cox <[email protected]> wrote:
>>> Applying -encode- to several variables is a little dangerous. If the
>>> values "A" to "D" occur for every variable and "E" occurs only for
>>> those variables for which it is possible, and for all of them, you
>>> should be fine. But suppose the only answers that occur for one
>>> variable are "A", "C", "D". Then those will be, by default, mapped to
>>> 1,2,3. -encode- has by default no intelligence that spots that "B" is
>>> missing and decides that the appropriate coding is 1, 3, 4. You would
>>> need to define value labels in advance and specify those as the labels
>>> to be used.
>>>
>>> Note also -multencode- (SSC).
>>>
>>> Nick
>>> [email protected]
>>>
>>>
>>> On 7 February 2014 08:04, Ronnie Babigumira <[email protected]> wrote:
>>>> encode worked just fine. What you see as the "exact same variable" is
>>>> just the label
>>>>
>>>> *****
>>>> clear *
>>>> input id str1 qn1 str1 strqn3
>>>> 1 A D
>>>> 2 A A
>>>> 3 E B
>>>> 4 B C
>>>> end
>>>>
>>>> encode qn1, g(nqn1)
>>>> list
>>>> list, nolabel
>>>> *****
>>>>
>>>> Ps: note the label option of encode which allows you to provide your own label
>>>>
>>>> On Fri, Feb 7, 2014 at 1:59 AM, Katherine Picho <[email protected]> wrote:
>>>>> I have a huge dataset which has test data with multiple choice
>>>>> questions. 2 questions have choices A -E, and the rest have 4 options
>>>>> A-D
>>>>>
>>>>> I was looking to convert these options to numeric values with A
>>>>> corresponding to 1, B=2, etc.
>>>>>
>>>>> I'm using stata 12.
>>>>>
>>>>> I tried using the egen newvar= group (oldvar) command, it seems to
>>>>> work for some questions but not others. For instance the sequence of
>>>>> the 1st 5 students' answers for question 18 are AAAAA, which should
>>>>> translate to 5 consecutive 1s..but I get consecutive 2s instead.
>>>>>
>>>>> For another test question 10, a value of 6 is reported for one
>>>>> observation which actually has a letter value of C which should
>>>>> correspond to a value of 3.
>>>>>
>>>>> I also tried encode oldvar, gen (newvar)
>>>>> but I get the exact same variable data as in the original (i.e.
>>>>> letters, not numbers) even though the data storage type now shows
>>>>> 'long'
>>>>>
>>>>> I've checked to make sure there is consistency in data entry and there
>>>>> appears to be; i.e. all responses are entered in capital letters, and
>>>>> there is no mix of numeric and letters in the same variable/ column.
>>>>>
>>>>> What am I doing wrong? Any thoughts on this problem would be highly
>>>>> welcome as I dread the idea of having to manually convert these
>>>>> letters to numbers!
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