This article presents the results of a qualitative research with a group of 15 university students of social sciences on informal inferential reasoning developed in a computer environment on concepts involved in the confidence intervals. The results indicate that students developed a correct reasoning about sampling variability and visualized…

This study focuses on the development of four tertiary introductory statistics students' informal inferential reasoning while engaging in data driven repeated sampling and resampling activities. Through the use of hands-on manipulatives and simulations with technology, the participants constructed empirical sampling distributions in order to…

The research reported here uses a pre/post-test model and stimulated recall interviews to assess teachers' statistical reasoning about comparing distributions, when enrolled in a graduate-level statistics education course. We discuss key aspects of the course design aimed at improving teachers' learning and teaching of statistics, and the…

In this study, we examined the ways in which teachers' statistical knowledge is enacted during instructional practice. Using classroom video recordings from three middle-grades' teachers, we qualitatively analyzed the conversations around a task designed to develop students' knowledge of statistical sampling. Our analyses showed how teachers'…

As part of an interview protocol investigating teachers' pedagogical content knowledge (PCK) in statistics, 40 teachers were presented with a newspaper article reporting a phone-in survey about the legalisation of marijuana. The article and a question about the reliability of the sample had earlier been used in student surveys, and three student…

Twenty Monte Carlo studies on multiple comparison (MC) techniques were conducted to examine which MC technique was the "method of choice." The results from these studies had several apparent contradictions when different techniques were investigated under varying sample size and variance conditions. Box's coefficient of variance…

We distinguish two conceptions of sample and sampling that emerged in the context of a teaching experiment conducted in a high school statistics class. In one conception "sample as a quasi-proportional, small-scale version of the population" is the encompassing image. This conception entails images of repeating the sampling process and…

This investigation had two major purposes. The first was to explore the use of an inferential technique called Tukey's Jackknife in establishing a confidence interval about cooefficient alpha reliability. The second purpose was to study the robustness of the Feldt and the jackknife procedures when the data fails to satisfy usual normality…

This paper presents a summary of action research investigating statistics students' understandings of the sampling distribution of the mean. With four sections of an introductory Statistics in Education course (n=98 students), a computer simulation activity (R. delMas, J. Garfield, and B. Chance, 1999) was implemented and evaluated to show…

There is a growing body of evidence indicating that people often overestimate the similarity between characteristics of random samples and those of the populations from which they are drawn. This paper: reviews studies that have attempted to determine whether the basic heuristic employed in thinking about random samples is passive and descriptive…

In true experiments in which sample material can be randomly assigned to treatment conditions, most researchers presume that the condition of equal sample sizes is statistically desirable. When one or more a priori contrasts can be identified which represent a few overriding experimental concerns, however, allocating sample material unequally will…

A methodology for estimating descriptive statistics, specifically the mean and the variance, from a sample that is not normally drawn is described. The method involves breaking the sample down into subgroups and weighting the descriptive statistics associated with each subgroup by the proportion of the population that the subgroup represents. This…

With the help of widely available microcomputers, it is possible to demonstrate certain statistical phenomena which students of statistics are usually expected to take on faith. Two demonstrations are described. In the first demonstration, three common types of sampling (simple random, biased, and stratified-random) are used to compare statistics…

An important topic presented in introductory statistics courses is the estimation of population parameters using samples. Students learn that when estimating population variances using sample data, we always get an underestimate of the population variance if we divide by n rather than n-1. One implication of this correction is that the degree of…

Ten high-ability middle school students participated in a 13 week enrichment program on inferential statistics. Consistent with the NCTM Standards, classes emphasized problem solving in real world contexts and the communication of mathematical ideas. Students struggled with written assignments, yet worked effectively in pairs, small groups, and…