Which type of assessment includes a variety of samples of students’ work collected over time?

The correct answer is a portfolio, as it specifically refers to a collection of a student's work compiled over time to showcase their progress, achievements, and skills in a particular area. Portfolios provide a comprehensive view of a student’s learning journey, allowing educators to assess not just the end results but also the development and effort that contributed to those results. They often include a variety of formats, such as essays, projects, and reflections, demonstrating diverse achievements and competencies.

In contrast, summative assessment typically evaluates student learning at the end of an instructional unit to measure understanding and learning outcomes, without the ongoing collection aspect. Performance assessment focuses on the execution of tasks or projects but does not necessarily include a broad range of work or a chronological collection. Standardized assessment involves uniform tests administered and scored in a consistent manner to compare performance across different student populations, which is not reflective of an individual’s ongoing development over time. Thus, while they all serve important roles in education, they do not encapsulate the iterative and holistic nature of a portfolio.