Combating Effort Avoidance in Computer Adaptive Practicing: Does a Problem Skipping Restriction Promote Learning?

Effort is key in learning, evidenced by its omnipresence in both empirical findings and educational theories. At the same time, students are consistently found to avoid effort. In this study, we investigate whether limiting effort avoidance improves learning outcomes, and explore for whom this would be the case. In a large-scale computer adaptive practice system for primary education, over 150,000 participants were distributed across four conditions in which a problem-skipping option was delayed for 0, 3, 6, or 9 seconds. The results show that after a 14 week period, no average treatment effects in learning outcomes can be found between conditions. A substantive typology of students, based on the expected target mechanisms of the intervention, neither shows consistent conditional average treatment effects. Nevertheless, the substantive typology is shown to be meaningful, as the different types—toilers, skippers, and rushers—differ with respect to their learning outcomes. We argue that although the scale of the experiment suggests a precise null finding, the cumulative nature of the effect of problem skipping cautions against generalizing this finding to sustained intervention.

Segregation, Integration, and Death: Evidence from the Korean War

How does the design of military institutions affect who bears the costs of war? We answer this question by studying the transformative shift from segregated to integrated US military units during the Korean War. Combining new micro-level data on combat fatalities with archival data on the deployment and racial composition of military battalions, we show that Black and white soldiers died at similar rates under segregation. Qualitative and quantitative evidence provides one potential explanation for this counterintuitive null finding: acute battlefield concerns necessitated deploying military units wherever soldiers were needed, regardless of their race. We next argue that the mid-war racial integration of units, which tied the fates of soldiers more closely together, should not alter the relative fatality rates. The evidence is consistent with this expectation. Finally, while aggregate fatality rates were equal across races, segregation enabled short-term casualty discrepancies. Under segregation there were high casualty periods for white units followed by high casualty periods for Black units. Integration eliminated this variability. This research note highlights how enshrining segregationist policies within militaries creates permissive conditions for either commanders' choices, or the dictates and variability of conflict, to shape who bears war's costs.

Investigating Open-access Booking in New Brunswick Occupational Therapy

Background. Open-access booking (OAB) describes administrative changes to improve system efficiency. However, OAB studies have focused on GP practices and have not applied OAB to other health care services. Purpose. The purpose of the study was to investigate the associations between OAB and administrative outcomes in the Saint John region. Method. Evaluators compared three years of pre-OAB data against two years of post-OAB data using an interrupted-time series design (February 2014–January 2019). Findings. OAB was associated with a 12% jump in the likelihood of being discharged within three months even though clients received an equivalent level of service. OAB was not associated with more missed appointments (∼8% vs. ∼7%). While OAB was not associated with reduced wait times, the post-OAB period handled a larger number of client referrals, which may explain the null finding. Implications. OAB shows potential for improving administrative outcomes, but further research is needed.

The Two-step Model of Clustered Democratization

Does democratization diffuse? For over two decades, numerous studies have asserted that democratization diffuses across countries but recent research has challenged this claim. Most recently, work by Brancati and Lucardi has buttressed this null finding by demonstrating that an oft assumed mechanism for the diffusion of democratization—the diffusion of pro-democracy protests—lacks empirical support. We review this contribution in the context of recent research and pose the question: if democratization does not diffuse, then why does democratization cluster in time and space? The answer, we argue, is that democratization occurs in two steps. First, common shocks, economic or political, lead to regime collapse. Then, diffusion does emerge in a second step: new elites are more likely to install a democracy following a regime collapse if neighboring countries have recently democratized. We present evidence from democratic transitions in 125 autocracies between 1875 and 2014.

The role of input in native Spanish Late learners’ production and perception of English phonetic segments

This study evaluated the effect of input variation on the production and perception of English phonetic segments by native Spanish adults who had immigrated to the United States after the age of 16 years. The native Spanish (NS) participants were assigned to three groups of 20 each according to years of English input (years of U.S. residence multiplied by percent English use outside the home). Experiment 1 assessed the perceived relation between English and Spanish vowels. It yielded similar results for the NS groups designated “Low input” (M = 0.2 years of input), “Mid” (M = 1.2 years) and “High” (M = 3.0 years). Experiments 2–4 examined English vowel discrimination, vowel production and consonant discrimination. Apart from a modest improvement in vowel discrimination, these experiments showed little improvement as years of English input increased. One possible explanation for the essentially null finding of this study is that input matters little or not at all when an L2 is learned naturalistically following the closure of a critical period. Another possibility is that adequate native speaker input is crucial for L2 speech learning but the input differences evaluated here were insufficient to yield measurable improvements in performance. We conclude the article by illustrating a new technique that might be used to choose between these competing explanations.

Power and Vertical Positions in an Organization Chart: A Pre-Registered Replication Report of Study 3a and a Modification of Study 1a, Giessner & Schubert (2007)

Study 1a of Giessner and Schubert (2007) found a causal effect of vertical spatial cues on power judgments. Recent work showed that this was a false positive (Klein et al., 2018). Here, we test whether another paradigm (i.e., original Study 3a) can be replicated, and develop an adjusted paradigm of original Study 1a to clarify what kind of vertical spatial cues influence power judgments. Our current preregistered Study 1 confirms original Study 3a of Giessner and Schubert (2007). It shows that information about the power of a leader is represented spatially by placing the leader’s box higher in an organigram. Our current Study 2 distinguishes vertical ranks from magnitude of vertical spatial difference without changes in rank. The original Study 1a and the failed replication manipulated only magnitude while leaving rank equal. We confirm the null finding here. However, we also find that vertical rank order does indeed affect power judgments, again in a preregistered study, and in line with prior work. In sum, building on earlier work and the failed replication, we clarify that vertical rank order, but not magnitude of elevation, are associated with power judgments.

In the wake of a terrorist attack, do Americans’ attitudes toward Muslims decline?

When a terrorist attack occurs, a natural response may be increased public concern about terrorism. But when a self-described Muslim perpetrates a terrorist attack, do negative attitudes toward Muslims also increase? If so, is this effect conditional on the nature of people’s past personal experiences with Muslims? We present natural experiment data based on a 2015 web-based survey of 2105 non-Muslims in the US, a survey that happened to span the terrorist attacks in Paris on 13 November and San Bernardino on 2 December. We thus test Americans’ feelings toward Muslims immediately before and after both an international and a domestic terrorist attack. We find that, although the attacks significantly affected Americans’ concerns about radicalism both in the US and abroad, they did not negatively affect Americans’ thermometer feelings toward Muslims in the aggregate—a null finding conditioned only slightly by the nature of past personal experiences with Muslims.

On imputing UNHCR data

Dyadic data from the United Nations High Commissioner for Refugees (UNHCR) on the size of the global refugee population are widely used. However, for a large fraction of the refugee population, these data provide no information about refugees’ country of origin, which contributes to a high nominal rate of unreported values in the data. In this article, I demonstrate that two imputation approaches outperform the current standard approach, which assumes that all unreported values are zero. The first approach interpolates the unreported values, while the second predicts them based on trends observed in other dyads. Drawing on different types of information, the two approaches’ performance is similar. Replicating a published study on the effect of refugee crises on international war and peace, I demonstrate how both approaches strengthen the author’s findings and help to minimize the risk of a null finding.

No evidence for decreased foreign language effect in highly proficient and acculturated bilinguals

Bilinguals who consider moral problems in their foreign language tend to endorse causing harm to others that if that leads to good outcomes more than they do in their native language. Čavar and Tytus (2018) reported that this effect disappears when the decision maker is highly acculturated. We challenge the latter conclusion. Specifically, the experiment reported by Čavar and Tytus (2018) utilized unvalidated and potentially unreliable materials, was underpowered, and lacked a control group. Moreover, the re-analysis of the statistical test shows that it fails to convincingly support the reported null finding. We conclude that further examination of the moral foreign language effect is needed to test its boundaries.