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As automated tools for grading programming assignments become more widely used, it is imperative that we better understand how students are utilizing them. Other researchers have provided helpful data on the role automated assessment tools (AATs) have played in the classroom. In order to investigate improved practices in using AATs for student learning, we sought to better understand how students iteratively modify their programs toward a solution by analyzing more than 45,000 student submissions over 7 semesters in an introductory (CS1) programming course. The resulting metrics allowed us to study what steps students took toward solutions for programming assignments. This paper considers the incremental changes students make and the correlating score between sequential submissions, measured by metrics including source lines of code, cyclomatic (McCabe) complexity, state space, and the 6 Halstead measures of complexity of the program. We demonstrate the value of throttling and show that generating software metrics for analysis can serve to help instructors better guide student learning.

An interlaboratory comparison using relative-humidity (RH) and temperature probes at three national measurement institutes and two accredited laboratories has been carried out. The work had three purposes: firstly, to establish the instruments' level of reproducibility and suitability for use as transfer standards within their specified range of operation; secondly, to show the agreement of a method of RH generation utilizing certified non-saturated salt RH standards when compared with a method of RH calibration using a chilled-mirror reference and platinum-resistance thermometers; and finally, from the results obtained it is possible to establish the equivalence between the participating laboratories, to the level of uncertainty achievable with the transfer standards used. A total of six RH probes were tested in two groups. The instruments of the first group were calibrated in the range from 10 %rh to 90 %rh at a temperature of 23 • C. The second group of instruments was measured in the same RH range, but at the temperatures of 5 • C, 23 • C, and 50 • C. The objective of the tests on the second group of instruments was to determine the effect of a wider operating temperature range on performance. This article presents and discusses the results of the 1697 comparison in the context of an international collaboration that provides confidence in the measurements performed by the participants within their respective accredited scopes and the ILAC or the CIPM mutual recognition arrangements.

Techniques for the evaluation of the spatial temperature and humidity performance criteria of climatic chambers are described within the various sections of the International Electrotechnical Commission (IEC) Standard IEC60068 applicable to environmental testing. This paper involves the comparison of three common measurement systems used to assess the performance of climatic chambers, as well as the development of methods for determination of uncertainty contributions, and subsequent propagation into an uncertainty analysis for each method. Methods for validating the performance of these chambers should include specific uncertainty contributions, such as fluctuations, homogeneity, radiation, sampling, and loading effects. These effects are discussed and evaluated as part of this work. The procedure, as detailed in IEC60068, was followed using a chilled-mirror dew-point hygrometer with nine platinum resistance thermometers, nine calibrated RH (relative humidity) and temperature probes, and nine calibrated RH and temperature wireless data logger modules. Loading effect and dew-point uniformity were evaluated empirically and the results discussed. A summary of the results obtained and the associated uncertainty calculations are described and compared. All three systems have their merits, and lower uncertainties in both temperature and %rh were obtained for the chilled-mirror system. Loading effect:The difference in temperature at any one point due to the presence of a load in the chamber space Radiation effect:Differences in the measured temperature due to the absorption or emission of different levels of thermal radiation by the temperature sensors Dew-point uniformity: The amount of variation in the dew-point temperature within the test space, equivalent to water vapor-pressure uniformity Gradient:Maximum difference in mean value, after stabilization at any moment in time between two separate points in the working space. Fluctuation:Change (from the mean) in temperature or humidity after stabilization from time to time at a point in space.