{smcl} {* 25march2006}{...} {cmd:help sqdes}{right:(SJ6-4: st0111)} {hline} {title:Title} {p2colset 5 11 13 2}{...} {p2col :{hi:sqdes} {hline 2} Describe sequence concentration}{p_end} {p2colreset}{...} {title:Syntax} {p 8 17 2} {cmdab:sqdes} {ifin} [{cmd:,} {it:options}] {synoptset 20}{...} {synopthdr} {synoptline} {synopt:{opt so}}apply same-order similarity{p_end} {synopt:{opt se}}apply same-elements similarity{p_end} {synopt:{opt graph}}display results graphically{p_end} {synopt:{opt gap:include}}include sequences with gaps in the tabulation{p_end} {synopt:{opt subseq:uence(a,b)}}use only subsequence between positions a and b{p_end} {synoptline} {title:Description} {pstd} {cmd:sqdes} is a way to describe the concentration of sequences in the dataset. Considering the limiting case when all respondents share the same sequence, one would speak of a high concentration of sequences, whereas one would speak of a low concentration if all observed sequences were unique. Hence, the more only a few sequences are shared by many respondents, the higher the concentration of sequences is, whereas the more sequences that are unique, the lower the concentration. {pstd}The command {cmd: sqdes} provides this and some further information about the concentration or diversification of sequences. {title:Options} {phang} {cmd:so} is used to request a frequency table, where similar sequences have been grouped together beforehand. The concept for similarity used with the option {opt so} is called same-order similarity, because it treats sequences where the elements appear in the same order. The sequence A-B-B-A would be treated identical to A-B-A-A, because the elements A and B appear in the same order in both sequences (first A, then B, and then A again). {phang}{cmd:se} is used to request a frequency table, where similar sequences have been grouped together beforehand. The concept for similarity used with the option {opt so} is called same-elements similarity, because it treats sequences that consist of the same elements as identical. Hence, with this option the sequence B-A-A-B would be treated as identical to A-B-B-A, because both sequences consist of the elements A and B. {phang}{cmd:graph} provides a simple vertical bar chart of the table presented with {cmd:sqdes}. Sequences are highly concentrated if many and/or high bars are on the right of the graph, and fairly unique if they are on the left. You can specify all options available for {helpb graph twoway bar} to further control the look of the graph. {p_end} {phang}{cmd:gapinclude} is used to include sequences with gaps in the tabulation. The default behavior is to drop sequences with gaps from the tabulation, because they cannot be used in the program {helpb sqom}. The term "gap" refers only to missing values on the element variable within a sequence. Sequences with missing values at the beginning and at the end of a sequence are included in any case. See {help sq##3:sq} for details.{p_end} {phang}{cmd:subsequence(a,b)} is used to include only the part of the sequence that is between position a and b, whereby a and b refer to the position defined in the order variable. {p_end} {title:Author} {pstd}Ulrich Kohler, WZB, kohler@wz-berlin.de{p_end} {title:Examples} {phang}{cmd:. sqdes} {phang}{cmd:. sqdes, so} {phang}{cmd:. sqdes, so graph} {title:Also see} {psee} Online: {helpb sq}, {helpb sqdemo}, {helpb sqset}, {helpb sqdes}, {helpb sqegen}, {helpb sqstat}, {helpb sqindexplot}, {helpb sqparcoord}, {helpb sqom}, {helpb sqclusterdat}, {helpb sqclustermat} {p_end}