Sentences with word «cusum»

As with cusum charts in quality control, it's unlikely that we are going to get an appropriate standard at first try.

Critics of cusum remain concerned over the ease with which it has been accepted by courts.

The concern over cusum goes much deeper, however.

Michael Farringdon, a computer scientist at the University College of Swansea's European Business Management School, and a co-author with Morton on cusum, says Canter's statistical arguments are suspect.

When it is used on a document, Morton says cusum identifies «consistent habits» in the author's use of language.

Farringdon's wife, Jillian, who is a researcher in linguistics, says she will publish new cusum findings in The Swansea Review and D H Lawrence Review this year.

He applies cusum technique to texts written by known authors, including some that had been analysed by Morton.

Compiled by David Canter, professor of psychology at the University of Surrey, it raises serious doubts over cusum as a forensic technique.

Critics have focused on two key questions: why should cusum work and what evidence is there that it does work?

Like Hardcastle, Canter is in no doubt about cusum analysis.

«This means in virtually half the cases, cusum analysts would have mistakenly reached the conclusion of multiple authorship,» says Canter.

Canter, who is a specialist in forensic psychology, says no aspect of human behaviour — even measurements of intelligence — has shown such a high level of consistency as that claimed for cusum.

In the current issue of Literary and Linguistic Computing, Michael Hilton, professor of computer science at the University of South Carolina and David Holmes of the University of the West of England, who is a specialist in the quantitative analysis of language, show that the «consistent habits» used by cusum can be overwhelmed by this noise.

Other questions have been raised over the way cusum findings are presented to juries.

He adds that his statistical analysis confirms that the subjective interpretation of cusum results are reliable.

How does the squared prediction error (or CUSUM if available) of the Keenleyside prediction compare to the errors of other predictions of other models made contemporaneously?

The two cusum segments are essentially straight, indicating that the data do indeed form two clearly different groups.

In Expert Evidence (No 3, p 93, 1992), Canter analyses more than 100 cusum charts using the «Spearman rank correlation test».

But now, questions have been raised about the validity of cusum.

In court, Morton said cusum had been applied to the statements of 2000 people and found to be valid in every case.

Faced with a scientific controversy as complex as that now raging over cusum can lawyers, judges and juries be expected to decide between the scientific and the specious?

Academic opposition to cusum would almost certainly have prevented it passing the Frye test, says Carson.

The cusum charts failed to reach this value in almost half the texts tested.

In court, Morton uses the cusum charts — graphs that are easy for juries to understand.

Hardcastle condemns the «deplorable lack of scientific rigour» used in cusum, and concludes that the technique «is ill - defined».

But when standard statistical techniques are applied to cusum charts, the results are far from encouraging.

It may sound far - fetched, but this is exactly what the Reverend Andrew Morton, a researcher in linguistic analysis at the University of Glasgow, claims for a procedure called «cusum» — a contraction of cumulative sum.

This provides a quantitative assessment of the agreement between the two lines on a cusum chart.

Morton's claim that cusum can detect as few as ten sentences inserted into a text has raised worries over the way normal variation in the way people write and speak, would create statistical «noise» in the technique's findings.

«In other words, the cusum comparisons would have mistakenly supported the claim for single authorship in two out of three cases.»

There is no shortage, however, of peer - reviewed research reaching altogether different conclusions about the reliability of cusum.

However, by plotting monthly data that has been adjusted for possible systematic changes, such as the temperature «sine wave» by simply subtracting the long term average for each month from each individual datum — which I call «monthly differences» — as its cumulative sum rather than in its original form, the cusum pattern that emerges is often quite striking.