On 25 May 2004 14:31:48 -0700, [EMAIL PROTECTED] (bielawski) wrote: >Q-Sort is used as the name of a sorting algotithm. It is common in UNIX >systems. The following reference comes from the UNIX manual page for qsort: > >Hoare, C.A.R., "Quicksort", The Computer Journal, 5:1, pp. 10-15, 1962. > >Is q-sort short for Quicksort?
It appears not. As far as I can tell, Q-Sort in the sense used by the original poster is a way of sorting items in order (by some criterion) by placing them in "piles" along a continuum (such as "strongly agree" to "strongly disagree"), Hoare's Quicksort works by taking one item and comparing other items to that one (so as to determine where the original item fits). Q-Sort is, in computer-science terms, more of a "radix sort", in that items are coarsely classified first, and then if necessary revisited for a finer classification. Cheers, Ken. >----- Original Message ----- >From: "Bruce Weaver" <[EMAIL PROTECTED]> >To: <[EMAIL PROTECTED]> >Sent: Tuesday, May 25, 2004 3:41 PM >Subject: Re: [edstat] Q-Sort / Q-methodology - What is "Q"? > > >> Neil wrote: >> > This may sound like a silly question, but for those of you are >> > familiar with Q-Sort Analysis / Q-Methodology, (a type of Factor >> > Analysis), does someone know what the "Q" actually stands for? >> > >> > I have found many journal articles and websites on this analysis/ >> > methodology, but have not been able to find the above information in >> > any of my sources. A definitive reference where this information can >> > be found will help. >> > >> > TIA >> >> I initially thought Neil was talking about "Q-mode factor >> analysis", as did some other respondents. David Garson >> describes Q-mode factor analysis as follows >> (http://www2.chass.ncsu.edu/garson/pa765/factor.htm): >> >> ------------------------------------------------------ >> Factor Analytic Data Modes >> >> * R-mode factor analysis. R-mode is by far the most >> common, so much so that it is normally assumed and not >> labeled as such. In R-mode, rows are cases, columns are >> variables, and cell entries are scores of the cases on the >> variables. In R-mode, the factors are clusters of variables >> on a set of people or other entities, at a given point of time. >> >> * Q-mode factor analysis, also called inverse factor >> analysis, is factor analysis which seeks to cluster the >> cases rather than the variables. That is, in Q-mode the rows >> are variables and the columns are cases (ex., people), and >> the cell entries are scores of the cases on the variables. >> In Q-mode the factors are clusters of people for a set of >> variables. Q-mode is used to establish the factional >> composition of a group on a set of issues at a given point >> in time. >> >> The Q-mode has the special problem of negative factor >> loadings. In conventional factor analysis of variables, a >> negative loading indicates a negative relation of the >> variable to the factor. In Q-mode factor analysis, a >> negative loading does not have a clear meaning. One common >> approach is to consider all cases with negative loadings as >> being in a cluster of their own. Some researchers consider >> Q-mode factor analysis suspect due to negative loadings, the >> possibility of singularities (columns with the same values), >> and ranking problems. Most researchers prefer to use a more >> accepted technique, such as some form of cluster analysis. >> ------------------------------------------------------ >> >> But I don't think this is what Neil was talking about. The >> following is from David Clark-Carter's book (reference given >> below), in a section called "Techniques to Measure Meaning" >> (p. 97): >> >> "Q-methodology is an approach to research which was devised >> by Stephenson (1953). It requires participants or judges to >> rate statements or other elements on a given dimension or on >> a given basis. One technique which Q-methodology employs is >> getting participants to perform Q-sorts. Typically a Q-sort >> involves participants being presented with a set of >> statements, each on an individual card, and being asked to >> place those statements on a dimension, such as /very >> important to me/ to /not imporant to me/." etc >> >> Clark-Carter refers to Kerlinger (1973), and says that >> "[Carl] Rogers (1951, 1961) has used Q-sorts in the context >> of counselling." >> >> Here's the Clark-Carter book info: >> >> Clark-Carter, D. (1997). Doing quantitative psychological >> research: From design to report. East Hove, Sussex: >> Psychological Press. >> >> Cheers, >> Bruce >> -- >> Bruce Weaver >> [EMAIL PROTECTED] >> www.angelfire.com/wv/bwhomedir/ >> >> . >> . >> ================================================================= >> Instructions for joining and leaving this list, remarks about the >> problem of INAPPROPRIATE MESSAGES, and archives are available at: >> . http://jse.stat.ncsu.edu/ . >> ================================================================= >> > > >. >. >================================================================= >Instructions for joining and leaving this list, remarks about the >problem of INAPPROPRIATE MESSAGES, and archives are available at: >. http://jse.stat.ncsu.edu/ . >================================================================= -- Ken Butler, Lecturer (Statistics) University of Toronto at Scarborough butler (at) utsc.utoronto.ca http://www.utsc.utoronto.ca/~butler . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
