I've been observing a 7th grade integrated science class at Lehi Junior High School. The first day I was there, the teacher gave a formal, summative assessment for their unit final. They used laptops to take a 15 question, multiple-choice quiz. The assessment also included one free response question on a separate sheet of paper where they had to draw and explain osmosis. It was definitely a valid assessment because they had covered the exact same information in class, she even reviewed with them the exact information right before they took the quiz. The quiz questions seemed reliable to me, and based on the positive scores most of the students got, I don't think they had any issues with the clarity of questions. It was practical since the classroom already had laptops, and they only used 1/2 sheet of paper each to answer the free response question. It wasn't entirely fair though. Even though each kid had the same test questions, some of them had a hard time logging in to the system, and some of them read faster than others. I'm sure this created an anxious environment for the ones who didn't finish as quickly as the others.
The teacher I observe does informal, formative assessments pretty much all of the time. She always has activities for the kids to do (matching, categorizing, etc), and she goes from group to group to see how they are doing, how much they are understanding, and helping them out whenever they have questions. This technique is super valid, since it's occurring while the instruction is happening, and it's fair because everyone in class has the same resources. I have noticed some instances of a lack of reliability though. This morning, the objective of the activity was for students to sort about 20 really small pictures into either "cells" "tissues" "organs" "organ systems" or "organisms". Most of the students knew what they were supposed to do, and probably would have gotten most of them right, if they could figure out what the tiny little pictures were supposed to be. As I was walking around the class, I found that the only help most of them needed was clarification to what they were looking at.
This article talks about the four points of an assessment we talked about, fairness, validity, practicality, and reliability, but it also adds a fifth element: usefulness. It talks about how an assessment should be useful to the student in their learning, and should provide feedback.
http://www2.rgu.ac.uk/celt/pgcerttlt/assessing/assess3.htm
