Reverse worded (RW) items are often used to reduce or eliminate acquiescence bias, but there is a rising concern about their harmful effects on the covariance structure of the scale. Therefore, results obtained via traditional covariance analyses may be distorted. This study examined the effect of the RW items on the factor structure of the abbreviated 18-item Need for Cognition (NFC) scale using confirmatory factor analysis. We modified the scale to create three revised versions, varying from no RW items to all RW items. We also manipulated the type of the RW items (polar opposite vs. negated). To each of the four scales, we fit four previously developed models. The four models included a 1-factor model, a 2-factor model distinguishing between positively worded (PW) items and RW items, and two 2-factor models, each with one substantive factor and one method factor. Results showed that the number and type of the RW items affected the factor structure of the NFC scale. Consistent with previous research findings, for the original NFC scale, which contains both PW and RW items, the 1-factor model did not have good fit. In contrast, for the revised scales that had no RW items or all RW items, the 1-factor model had reasonably good fit. In addition, for the scale with polar opposite and negated RW items, the factor model with a method factor among the polar opposite items had considerably better fit than the 1-factor model.

Many psychological scales written in the Likert format include reverse worded (RW) items in order to control acquiescence bias. However, studies have shown that RW items often contaminate the factor structure of the scale by creating one or more method factors. The present study examines an alternative scale format, called the Expanded format, which replaces each response option in the Likert scale with a full sentence. We hypothesized that this format would result in a cleaner factor structure as compared with the Likert format. We tested this hypothesis on three popular psychological scales: the Rosenberg Self-Esteem scale, the Conscientiousness subscale of the Big Five Inventory, and the Beck Depression Inventory II. Scales in both formats showed comparable reliabilities. However, scales in the Expanded format had better (i.e., lower and more theoretically defensible) dimensionalities than scales in the Likert format, as assessed by both exploratory factor analyses and confirmatory factor analyses. We encourage further study and wider use of the Expanded format, particularly when a scale’s dimensionality is of theoretical interest.

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The chlorophyll content is one of the most important traits selected by breeders, and it is controlled by quantitative trait loci (QTLs) derived from natural variations in rice. We analyzed the QTL controlling chlorophyll content by using 94 RILs derived from a cross between 2 japonica rice cultivars, Lijiangxintuanheigu (LTH) and Shennong265 (SN265). Twenty-two QTLs controlling chlorophyll content at tillering stage, heading stage, and maturity stage were detected, respectively. Among them, Rice cv. LTH had a positive allele only at 1 locus (qCTH4) on chromosome 4. Further analysis indicated that the genetic effect of qCTH4 was the net effects within the period from tillering to heading. The QTL qCTH4 controlling chlorophyll content from tillering to heading locates between RM255 and RM349 on chromosome 4 with a LOD score 19.41, and the QTL qCTH4 explains 61.42% of phenotypic variation. In order to eliminate the influence of other QTLs, 1 single residual heterozygous plant, RH-qCTH4, was selected based on the genotypes of 114 Simple Sequence Repeat (SSR) markers. Using the segregating population derived from RH-qCTH4 by self-crossing, this region was narrowed down to an interval between RM3276 and RM17494 in an approximately 771kb target region. These results are useful for map-based cloning of qCTH4 and for marker-assisted selection of high photosynthetic efficiency variety.