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regression analysis that takes into account the hierarchical structure of data
(Hox, 2002; Luke, 2004). Hierarchical data means that observations at
lower levels are nested within units at higher levels. In this study, ratings are
nested within raters. With nested data, there may be more variation between
raters than within raters, a violation of the independence of observations
assumption that underlies traditional multiple-regression analysis. MLM
addresses this problem, because it assumes independence of observations
between raters, but not between ratings within a rater (Hox, 2002;
Luke, 2004). MLM also allows the examination of the effects of rater
variables (e.g., experience) on holistic scores (main effects) and on the
relationships between the analytic and holistic scores (called cross- level
interaction effects in MLM; Hox, 2002).
The software program HLM 6.0 for Windows (Raudenbush, Bryk,
Cheong, & Congdon, 2004) was used to build and test various MLM
models, following procedures suggested by Hox (2002), before identifying
the final model that fit the data. In addition to the outcome variable, holistic
scores, the study included one rater-level (called Level-2 in MLM) predictor,
rater experience (coded 0 for novice and 1 for experienced), and seven
measures of essay features that constitute the Level-1 predictors. These
measures were the five categories in the analytic scale as well as essay length
(number of words per essay measured using the word count function in
Microsoft Word) and essay topic. The prompt was used as a measure of
essay topic (what the essay is about), with the study prompt coded 0 and
the sports prompt coded 1.
(From Barkaoui,
2010
)
If you use a test, questionnaire or interview prompts to collect your data,
include a copy of these as an appendix at the back of your work.
Procedures
Having described your participants and data collection instruments, you
now need to describe the procedures you followed; that is, what you did
and the order in which you did it. As with the instruments used, your
description of the procedures needs to be detailed enough to allow other
researchers to replicate your study, should they wish to do so. Often, the
procedures and the instruments employed as part of them are reported
together. This is illustrated nicely in the Barkaoui example above.
Here’s another description of procedure from an article by Silvia
Gennari:
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