Language matters: how normative expressions shape norm perception and affect norm compliance

Previous studies have used various normative expressions such as 'should', 'appropriate' and 'approved' interchangeably to communicate injunctions and social norms. However, little is known about whether people's interpretations of normative language differ and whether behavioural responses might vary across them. In two studies (total n = 2903), we find that compliance is sensitive to the types of normative expressions and how they are used. Specifically, people are more likely to comply when the message is framed as an injunction rather than as what most people consider good behaviour (social norm framing). Behaviour is influenced by the type of normative expression when the norm is weak (donation to charities), not so when the norm is strong (reciprocity). Content analysis of free responses reveals individual differences in the interpretation of social norm messages, and heterogeneous motives for compliance. Messages in the social norm framing condition are perceived to be vague and uninformative, undermining their effectiveness. These results suggest that careful choice of normative expressions is in order when using messages to elicit compliance, especially when the underlying norms are weak. This article is part of the theme issue 'Social norm change: drivers and consequences'.

A novel regression method for the analysis of multireader multicase-free-response receiver operating characteristics studies

In diagnostic radiology, the multireader multicase (MRMC) design and the free-response receiver operating characteristics (FROC) method are often used in combination. The cross-correlated data generated by the MRMC-FROC study leads to difficulties in the corresponding analysis, and the need to include covariates in the model further complicates the subsequent analysis. In this paper, we propose a regression approach based on three new measures with good interpretability. The correlation structure of the original test results is taken directly into account in the estimation procedure. The proposed method also allows the inclusion of continuous or discrete covariates. Consistent and asymptotically normal estimators are derived for the new measures. Simulation studies are conducted to evaluate the performance of the proposed approach. The simulation results show that the regression approach performs well under a wide range of scenarios. We also apply the proposed regression approach to a diagnostic study of computer-aided diagnosis in lung cancer.

Periapical Radiography versus Cone Beam Computed Tomography in Endodontic Disease Detection: A Free-response, Factorial Study

AIM

To assess and compare reader performance in interpreting digital periapical (PA) radiography and cone beam computed tomography (CBCT) in endodontic disease detection, using a free-response, factorial model.

MATERIALS AND METHODS

A reader performance study of 2 image test sets was undertaken using a factorial, free-response design, accounting for the independent variables: case type, case severity, reader type, and imaging modality. Twenty-two readers interpreted 60 PA and 60 CBCT images divided into 5 categories: diseased-subtle, diseased-moderate, diseased-obvious, nondiseased-subtle, and nondiseased-obvious. Lesion localization fraction, specificity, false positive (FP) marks, and the weighted alternative free-response receiver operating characteristic figure of merit were calculated.

RESULTS

CBCT had greater specificity than PA in the obvious nondiseased cases (P = .01) and no significant difference in the subtle nondiseased category. Weighted alternative free-response receiver operating characteristic values were higher for PA than CBCT in the subtle diseased (P = .02) and moderate diseased (P = .01) groups with no significant difference between in the obvious diseased groups. CBCT had higher mean FPs than PA (P < .05) in subtle diseased cases. Mean lesion localization fraction in the moderate diseased group was higher in PA than CBCT (P = .003). No relationships were found between clinical experience and all diagnostic performance measures, except for in the obvious diseased CBCT group, where increasing experience was associated mean FP marks (P = .04).

CONCLUSIONS

Reader performance in the detection of endodontic disease is better with PA radiography than CBCT. Clinical experience does not impact upon the accuracy of interpretation of both PA radiography and CBCT.