> -----Original Message----- > From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of Chad > Danyluck > Sent: Thursday, February 19, 2015 12:33 PM > To: r-help@r-project.org > Subject: Re: [R] Averaging column scores when participants vary in > number of observations > > I have a data set that includes the identity of a number of Video > Coders > who scored participants' behaviors in a video. Every participant was > scored > once, but some participants were randomly assigned to have their data > scored twice so I could calculate inter-rater reliabilities. I have > completed the reliability analyses and want to use the average score > for > participants who had their behavior coded twice. I'd like to create a > 'for > loop' or function that allows me to calculate these column means > iteratively because the number of observations is quite large (*N* = > 168). Given the organization of the data, with some participants on > multiple rows, I am not sure how to proceed. > > The original data looks something like this: > > Participant ID Video Coder Score > Observation A 1 Donald 4 > Observation B 1 Tracy 5 > Observation C 2 Donald 6 > Observation D 3 Sam 2 > Observation E 3 Tracy 3 > Observation F 4 Donald 2 > Observation G 4 Tracy 1 > Observation H 5 Sam 8 > > When the data processing is completed, I would like the new data set to > look like this: > > Participant ID Score > 1 4.5 > 2 6 > 3 2.5 > 4 1.5 > 5 8 > > Any tips or suggestions would be appreciated. > > Kind regards, > > Chad
How about something like aggregate(Score ~ Participant_ID, data=rating, mean) hope this is helpful, Dan Daniel J. Nordlund, PhD Research and Data Analysis Division Services & Enterprise Support Administration Washington State Department of Social and Health Services ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
