High-School Students' Attitudes Regarding Procedural Abstraction

During the last decade a new computer science curriculum has been taught in Israeli high schools. This curriculum introduces CS concepts and problem-solving methods independently of specific computers and programming languages, along with the practical implementation of those concepts and methods encountered in actual programming languages. The advanced study unit of the curriculum, Software Design, introduces the students to various aspects of software systems design through the use of abstract data types (ADTs). One main goal of the unit is to develop abstract thinking skills and problem-solving abilities. More specifically, the unit presents principles such as procedural abstraction, data abstraction, information hiding, modularity, efficiency, and reuse of code.We present the results of a preliminary study whose aim was to assess students' attitudes regarding procedural abstraction. The research population consisted of high-school students who attended the Software Design course (beginners), and a control group of undergraduate CS students (advanced). The results of the study clearly indicated a significant difference between the attitudes of the two groups. We found that the advanced students preferred algorithms that were formulated to some extent with high-level abstraction; however, they encountered a cognitive barrier when dealing with algorithms that they had evaluated as too abstract for them. However, beginners felt more comfortable with algorithms with low-level abstraction. Nevertheless they showed open-mindedness toward some degree of procedural abstraction. The results of the study were used to design scaffolding problem-solving tools for algorithm development, utilizing procedural abstraction techniques that can be adapted to various student populations (Haberman, B. (2002) SIGCSE Bulletin, 34(4), 60–64).     

Subscores Based on Classical Test Theory: To Report or Not to Report

There is an increasing interest in reporting subscores, both at examinee level and at aggregate levels. However, it is important to ensure reasonable subscore performance in terms of high reliability and validity to minimize incorrect instructional and remediation decisions. This article employs a statistical measure based on classical test theory that is conceptually similar to the test reliability measure and can be used to determine when subscores have any added value over total scores. The usefulness of subscores is examined both at the level of the examinees and at the level of the institutions that the examinees belong to. The suggested approach is applied to two data sets from a basic skills test. The results provide little support in favor of reporting subscores for either examinees or institutions for the tests studied here.     

An NCME Instructional Module on Subscores

The purpose of this ITEMS module is to provide an introduction to subscores. First, examples of subscores from an operational test are provided. Then, a review of methods that can be used to examine if subscores have adequate psychometric quality is provided. It is demonstrated, using results from operational and simulated data, that subscores have to be based on a sufficient number of items and have to be sufficiently distinct from each other to have adequate psychometric quality. It is also demonstrated that several operationally reported subscores do not have adequate psychometric quality. Recommendations are made for those interested in reporting subscores for educational tests.     

‘These are not the realities I imagined’: an inquiry into the lost hopes and aspirations of beginning teachers

The Program for Excellence in Teaching (PET) conducted in Israel aspires towards training excellent teachers but also towards creating agents of change within the educational system. This qualitative study, focusing on 21 students and beginning teachers who participated in the PET at a certain college of education in Israel, examines their professional expectations and the disparity between intentions and implementations that happens as the beginning teachers encounter the reality in schools. The article suggests three factors that address this disparity: the participants’ positive conception of the educational system, the isolation of the beginning teachers, and the induction process they must undergo. This article proposes various innovative recommendations for coping with this situation.     

Studying Score Stability with a Harmonic Regression Family: A Comparison of Three Approaches to Adjustment of Examinee‐Specific Demographic Data

For assessments that use different forms in different administrations, equating methods are applied to ensure comparability of scores over time. Ideally, a score scale is well maintained throughout the life of a testing program. In reality, instability of a score scale can result from a variety of causes, some are expected while others may be unforeseen. The situation is more challenging for assessments that assemble many different forms and deliver frequent administrations per year. Harmonic regression, a seasonal‐adjustment method, has been found useful in achieving the goal of differentiating between possible known sources of variability and unknown sources so as to study score stability for such assessments. As an extension, this paper presents a family of three approaches that incorporate examinees' demographic data into harmonic regression in different ways. A generic evaluation method based on jackknifing is developed to compare the approaches within the family. The three approaches are compared using real data from an international language assessment. Results suggest that all approaches perform similarly and are effective in meeting the goal. The paper also discusses the properties and limitations of the three approaches, along with inferences about score (in)stability based on the harmonic regression results.     

The Utility of Augmented Subscores in a Licensure Exam: An Evaluation of Methods Using Empirical Data

Will subscores provide additional information than what is provided by the total score? Is there a method that can estimate more trustworthy subscores than observed subscores? To answer the first question, this study evaluated whether the true subscore was more accurately predicted by the observed subscore or total score. To answer the second question, three subscore estimation methods (i.e., subscore estimated from the observed subscore, total score, or a combination of both the subscore and total score) were compared. Analyses were conducted using data from six licensure tests. Results indicated that reporting subscores at the examinee level may not be necessary as they did not provide much additional information over what is provided by the total score. However, at the institutional level (for institution size ≥ 30), reporting subscores may not be harmful, although they may be redundant because the subscores were predicted equally well by the observed subscores or total scores. Finally, results indicated that estimating the subscore using a combination of observed subscore and total score resulted in the highest reliability.     

Small‐Sample Equating Using a Synthetic Linking Function

This study addressed the sampling error and linking bias that occur with small samples in a nonequivalent groups anchor test design. We proposed a linking method called the synthetic function, which is a weighted average of the identity function and a traditional equating function (in this case, the chained linear equating function). Specifically, we compared the synthetic, identity, and chained linear functions for various‐sized samples from two types of national assessments. One design used a highly reliable test and an external anchor, and the other used a relatively low‐reliability test and an internal anchor. The results from each of these methods were compared to the criterion equating function derived from the total samples with respect to linking bias and error. The study indicated that the synthetic functions might be a better choice than the chained linear equating method when samples are not large and, as a result, unrepresentative.     

How Learning Logic Programming Affects Recursion Comprehension

Recursion is a central concept in computer science, yet it is difficult for beginners to comprehend. Israeli high-school students learn recursion in the framework of a special modular program in computer science (Gal-Ezer & Harel, 1999). Some of them are introduced to the concept of recursion in two different paradigms: the procedural programming paradigm and the logic programming (LP) paradigm. Here we discuss the implication of first learning recursion in LP on the students’ understanding of the concept. The declarative approach for teaching recursion in logic programming seems to enhance students’ recursion comprehension. We found that students who learned recursion in LP before learning it in a procedural paradigm differed, in terms of their mental models of recursion, from those who were acquainted with recursion in procedural programming only. More of the LP students possessed an adequate model of recursion as a process than did the non-LP students. Moreover, the LP students also attained a unique conception of recursion as a tool for knowledge representation.