Chemistry is a lab science. And that means that it is critical that students understand how to conduct a variety of lab procedures and that they acquire specific skill sets. The best means of acquiring those skill sets is by doing them ... in the lab. But we thought we might be able to help out and that's the reason for a Concept Builder on Lab Procedures.

This Concept Builder took a lot more forethought than most. We would like to explain some of the considerations that were made in its design. First, we assumed its usage would occur near the beginning of the course as opposed to the middle or end of the course. As such, we made an effort to select procedures that were most commonly acquired at the beginning of the course and used throughout the course. While we will quickly admit that performing a titration and using a burette is a critical lab skill, it is typically not learned at the beginning of most introductory chemistry courses; nor is it used throughout the course. The same can be said of many other critical lab skills. Second, we recognize that the lab skills used by a course in one school will differ considerably from the lab skills used by a course in another school. One school may have glass pipets with pipet bulbs while a second school has glass pipets with pipet fillers and a third school may have plastic transfer pipets. The availability of equipment (or lack thereof) and the type of equipment that are available will impact the set of skills students will be acquiring. This factored into some of the questions we chose not to ask.

We were able to quickly identify two lab skills that were often used and also emphasized early in a course - using a digital mass balance and using a Bunsen burner. We also identified measurement as being a commonly used skill. And finally, the transfer of solids or solutions from a bottle to a beaker or a flask requires a set of skills that could be emphasized in a Concept Builder.

There are four activities in this Concept Builder. Those four activities are differentiated as follows:

• Using a Mass Balance: Question Groups 1-4 ... Questions focus on how to use a Tare button and a weigh boat and the importance of reporting trailing zeroes.
• Using a Bunsen Burner: Question Groups 5-10 ... Questions focus on how to light a burner and how to adjust the air vents; attention is given to the importance of flame color and shape and how to adjust it and identifying the hottest location in the flame.
• Measuremnt: Question Groups 11-14 ... Questions target the importance of sighting head-on, reading from the bottom of a meniscus, and the importance of the estimated digit in a measurement.
• From Bottle to Beaker: Question Groups 15-17 ... Questions focus on how to mix acid and water and capping a bottle after use.

The questions from each group are shown on a separate page. Teachers are encouraged to view the questions in order to judge which activities are most appropriate for their classes. We recommend doing the activities in the order in which they are presented as they are scaffolded in such a manner that one builds upon the other. We also recommend that teachers do each activity to gain a feel for the level of cognitive rigor required of the student. 

Like all our Concept Builders, this Concept Builder utilizes a variety of strategies to make each student's experience different. The ordering of questions is random. The Question number assigned to each question is scrambled. For instance, two side-by-side students will not have the same question for question number three. And questions are organized into "groups" with questions within the same group being very similar (for instance, they target the same concept) but not identical. And finally, the answer options for Multiple Choice questions are always scrambled.

The Concept Builder also keeps track of student progress. It requires that students demonstrate a mastery of questions in each Question Group. In order to complete an activity, a student must correctly analyze each question of that activity. If a student's analysis is incorrect, then the student will have to correctly analyze two other questions in the Question Group in successive fashion in order to successfully complete the activity. This approach provides the student extra practice on questions for which they exhibited difficulty. As a student progresses through an activity, a system of stars and other indicators are used to indicate progress on the activity. Progress is displayed in the progress report on the right side of the Concept Builder. A star indicates a demonstration of mastery. A question with a red background indicates that the student has missed the question. And a question with a yellow background means that the student must get one more question from that Question Group correctly answered in order to obtain a star. When an activity is completed, the student will be awarded a Trophy. This Trophy is displayed on the Main Menu screen. These strategies make the Concept Builder an ideal addition to the 1:1 classroom and other settings in which computers are readily available. 

The most valuable (and most overlooked) aspect of this Concept Builder is the Help Me! feature. Each question group is accompanied by a Help page that discusses the specifics of the question. This Help feature transforms the activity from a question-answering activity into a concept-building activity. The student who takes the time to use the Help pages can be transformed from a guesser to a learner and from an unsure student to a confident student. The "meat and potatoes" of the Help pages are in the sections titled "How to Think About This Situation:" Students need to be encouraged by teachers to use the Help Me! button and to read this section of the page. A student that takes time to reflect upon how they are answering the question and how an expert would think about the situation can transform their naivete into expertise.