An investigation into the comparable effectiveness of two tests of writing administered to college-level English as a Second Language students: The Computerized Placement Test and holistically scored essay exams

This dissertation describes the findings and implications of a correlational analysis. Scores earned on the Computerized Placement Test (CPT), sentence skills, were compared to essay scores of advanced English as a Second Language (ESL) students. As the CPT is designed for native speakers of English, it was hypothesized that it could be an invalid or unreliable instrument for non-native speakers. Florida community college students are mandated to take the CPT to determine preparedness, as are students at many other U.S. and Canadian colleges. If incoming students score low on the CPT, they may be required to take up to three semesters of remedial coursework. It is essential that scores earned by non-native speakers of English accurately reflect their ability level. They constitute a large and growing body of non-traditional students enrolled at community colleges.^ The study was conducted at Miami-Dade Community College, Wolfson Campus, fall 1997. Participants included 106 advanced ESL students who took both the CPT sentence skills test and wrote final essay exams. The essay exams were holistically scored by trained readers. Also, the participants took the Placement Articulation Software Service (PASS) exam, an alternative form of the CPT. Scores on the CPT and essays were compared by means of a Pearson product-moment correlation to validate the CPT. Scores on the CPT and the PASS exam were compared in the same manner to verify reliability. A percentage of appropriate placements was determined by comparing essay scores to CPT cutoff score ranges. Finally, the instruments were evaluated by means of independent-samples t-tests for performance differences between gender, age, and first language groups.^ The results indicate that the CPT sentence skills test is a valid and reliable placement instrument for advanced- level ESL students who intend to pursue community college degrees. The correlations demonstrated a substantial relationship between CPT and essay scores and a marked relationship between CPT and PASS scores. Appropriate placements were made in 86% of the cases. Furthermore, the CPT was found to discriminate equally among the gender, age, and first language groups included in this study. ^

A methodology to estimate time varying user responses to travel time and travel time reliability in a road pricing environment

Road pricing has emerged as an effective means of managing road traffic demand while simultaneously raising additional revenues to transportation agencies. Research on the factors that govern travel decisions has shown that user preferences may be a function of the demographic characteristics of the individuals and the perceived trip attributes. However, it is not clear what are the actual trip attributes considered in the travel decision- making process, how these attributes are perceived by travelers, and how the set of trip attributes change as a function of the time of the day or from day to day. In this study, operational Intelligent Transportation Systems (ITS) archives are mined and the aggregated preferences for a priced system are extracted at a fine time aggregation level for an extended number of days. The resulting information is related to corresponding time-varying trip attributes such as travel time, travel time reliability, charged toll, and other parameters. The time-varying user preferences and trip attributes are linked together by means of a binary choice model (Logit) with a linear utility function on trip attributes. The trip attributes weights in the utility function are then dynamically estimated for each time of day by means of an adaptive, limited-memory discrete Kalman filter (ALMF). The relationship between traveler choices and travel time is assessed using different rules to capture the logic that best represents the traveler perception and the effect of the real-time information on the observed preferences. The impact of travel time reliability on traveler choices is investigated considering its multiple definitions. It can be concluded based on the results that using the ALMF algorithm allows a robust estimation of time-varying weights in the utility function at fine time aggregation levels. The high correlations among the trip attributes severely constrain the simultaneous estimation of their weights in the utility function. Despite the data limitations, it is found that, the ALMF algorithm can provide stable estimates of the choice parameters for some periods of the day. Finally, it is found that the daily variation of the user sensitivities for different periods of the day resembles a well-defined normal distribution.