Chalk and Talk 

Several years ago a fellow HVAC instructor told me he had been strongly encouraged by his immediate supervisor to do more lecturing. To the academically trained supervisor, working with students in the lab didn’t look like teaching, it looked like training. In the supervisor’s mind, training was a lower level pursuit – akin to monkey see monkey do. The school had just transitioned from a Technical School to a Technical Collage and they wanted to look like a college. 

The instructor was asking for any help I could offer, especially along the lines of “chalk and talk”, his description of what he felt was being asked of him. I think that phrase perfectly embodies why so many students really don’t get a lot out of lectures – they are just observers, not participants. The instructor is writing stuff on the board and talking while the students are just passive observers.  In the days of chalk boards, the instructor was not even facing the class when they were writing. It sometimes seemed like the teacher was engrossed in their own thoughts while they stare at the board and talk to no one in particular. 

We have advanced a bit since then. At least with Powerpoint presentations we are usually facing the class, even if we are staring at our computer monitor most of the time. However, it is possible to lecture and still rise above the mind-numbing norm of a monologue delivered to a captive audience of passive observers.  

Begin by facing your audience and making eye contact with people long enough so they feel you are speaking to them personally. If you are using a Powerpoint presentation, be familiar enough with the presentation and the material that you don’t have to read the notes while looking at the screen. It is OK to look at the screen occasionally, but if your discussion is just straight out reading the notes it will be boring no matter how good the presentation is.

Use voice inflection and hand motion to convey personal interest in your subject matter. How do you expect your class to maintain interest if YOU think the talk is boring.

Stop and take a breath. One dead give away of a nervous speaker is someone who has rehearsed their speech so much that all the words come out in a rapid-fire regurgitation that indicates they are just repeating memorized phrases, not really thinking about they are saying.

Whenever possible, involve your audience. People learn more if they do more. Ways to involve the class could include group questions, prompts for input, or even direct questions to individual students if you know them well enough. Be careful with the last suggestion, the goal is to include the students, not intimidate or embarrass them.

Use visual aids. This is pretty easy to do today. Just be careful not to overdo the videos and pictures you share. You should not be handing your class over to professor YouTube, just showing snippets that enhance and reinforce your talk.

When using online material, make sure and watch it yourself first. Even though you are not the person in the video, if you show it to your class you are in effect endorsing it. There are some things online that you don’t want to be associated with. 

Finally, this is an HVACR class. It is perfectly OK to have gauges, meters, gas valves, compressors, or any other tools or parts you want as visual aids. If you are talking about meters, every student should have one in their hands. You can even do some small exercises during the lesson. Remember, people learn by doing, so have the students do something. No, this is not your typical college class – it is a hell of a lot more interesting.

Human Search Engine

 Instructors worry about not knowing all the answers. I know that I do. Let me put you at ease. You don’t have to know all the answers to be an effective instructor. In fact, I feel that anyone who knows all the answers hasn’t asked enough questions. Our job as instructors is not to be a human search engine, but to teach students how to search for answers on their own. In short, to help students become more proficient at the learning process, specifically applied to our field of HVACR. To be clear, I am not suggesting that instructors do not need to be competent in HVACR. Nor am I saying you shouldn’t want to know as many answers as possible. Just that knowing every answer a student might ask is not necessary. Discomfort with areas where you don’t know the answers can sometimes cause instructors to cling to the specific areas of information they already know and refuse to broaden their scope. This is particularly true when it comes to new technology and industry developments. I believe this is an unconscious effort to “know everything” by limiting the scope of knowledge you expose yourself and your students to. Venturing into areas of new development can be uncomfortable because you don’t have as many answers at the ready. However, it is perfectly OK to tell a student that you don’t know the answer to a question they ask. Help them by directing them to resources where they might find answers. They are going to need research skills when they enter the field. Teaching students to learn on their own is probably the most important thing you can possibly teach them. On those many occasions when you DO know the answer, it can be more helpful to guide them through a search process than to simply hand them the answer. People tend to remember things they discover on their own more than things that people tell them. It takes discipline to do this. Providing the answer immediately basically concludes the interaction with the student. Asking leading questions or discussing relevant informative resources makes the interaction more of a dialogue and requires more student participation. It definitely takes a little longer, but provides a better long-term result. Remember, students learn more by what THEY DO, than by what you do.  

Gigabit vs Dialup

 

When lecturing, you should be more interested in ensuring the students understand what you are saying than covering a specific amount of material. Even if you manage to vocalize every important piece of information about a particular subject, it is largely a wasted effort if the students are not receiving the information. Your job is not to state all relevant facts, but to communicate them to the students. It is easy for us to transmit data faster than the students can absorb it. Remember, you have seen all this information before, probably said it all before, many times. You are not having to mentally connect the facts into a logical framework because you have already done that. However, the students who are hearing it for the first time have to comprehend each statement and then tie the different statements together in some logical manner in order to really understand what they are hearing. Help them comprehend the information by including analogies, similes, and connecting statements. One of the most powerful teaching techniques is to introduce new concepts and ideas using things people already know and understand. For example, “the refrigeration system moves heat from one place to another, much like a sponge can absorb water in one place and then release it in another when you squeeze it.” Like all analogies, it is imperfect, but it starts the process of thinking about absorbing heat in one place and releasing it somewhere else. Once you get that point across you can start talking about what the refrigerant does to absorb heat. Maybe boil some water in a flask. Learning is not just collecting data, it is making mental connections between the data points to develop new concepts. This takes time. If you are talking at gigabit speed while your students are listening on dial-up, most of the information will be lost. I have been guilty of this. I can recall asking students questions at the end of a one hour lecture only to discover that they did not really understand something that I said 15 minutes into my lecture. So although I discharged my duty to cover everything, really, I just wasted everyone’s time – including mine! So when lecturing, take some time along the way to ask a few questions and engage in some dialogue with the students to make sure your message is being received. Remember, the idea is not to demonstrate your knowledge, but to help the students increase theirs.

Layered Learning

One common problem with teaching and learning HVACR is that there is just so much material to master. It is easy to drown the students in details if you are not careful. When I was using a text which presents enthalpy diagrams in its early chapters on basic refrigeration, students would come up to me and ask for drop slips after reading the chapter. They looked at the PH diagrams and concluded that they just were not smart enough for HVACR. It was just way too much information for them to comprehend while they were still wrestling with refrigerant boiling while it is cold! The real skill in presenting HVACR subject matter is to take inherently complex material and break it down into a series of comprehensible lessons, without leaving out material. Presenting information in stages, at a rate which most students can more easily digest is preferable to feeding them the whole enchilada at once and causing cognitive indigestion. You can still reach the peak, but you have to get to base camp first.

Electricity is a perfect example. We start with the basic concepts of voltage, current, resistance, and simple circuits. If you think of a simple balance beam with voltage in the middle – if resistance goes up, current goes down. Students can in fact understand how current, voltage and resistance are related without using any formulas. Similarly, you don’t have to bring in Ohm’s Law to understand the concepts of source, path, and load. In fact, I believe circuits are best approached at first without discussing Ohm’s Law. Students can build circuits and operate them to get a mental concept of how switches  and loads behave. They can even build series and parallel circuits to see how they differ: all without formulas. Then AFTER the students understand the basic concept of an electrical circuit, you introduce Ohm’s Law as a mathematical description of a circuit. Now they have something real to relate to the parts of the formula and it is less abstract. You can even build circuits with heaters and take measurements to demonstrate how Ohms Law works.

After students have learned to solve Ohm’s Law problems, then we tell them that Ohm’s Law does not work in most AC circuits. At first, we don’t discuss the effects of alternating current, inductive, and capacitive reactance. It is just too much to take in at once. However, since these concepts have far more to do with most air conditioning circuits than Ohm’s Law, we can’t really afford to ignore them. The effect of inductive reactance can be demonstrated by operating a small motor in a circuit and comparing its resistance, current, and voltage. You can have students build circuits that demonstrate the effect of inductive and capacitive reactance and how they relate to each other. Depending on how much AC electricity you teach, you can put an oscilloscope on the circuits to show what happens in capacitive and inductive circuits (the teacher would be doing this.) Finally, you can bring in reactance and impedance calculations, although I must admit we do not have our Air Conditioning classes at Athens Tech doing LCR calculations. It’s a little like boiling a frog – you do it a little at a time. Before the students know it, they have learned some complex subject matter that would have sent them running for the exits if it had been presented all at once.

Making Connections

Most curriculums, courses, and books are organized in a manner that resembles house construction. You lay the foundation and then add to that foundation as the material gets progressively more complex. The idea is to present the information in an orderly manner so that complex concepts can be understood. I believe that teachers have been using this general scheme for centuries. I also believe teachers have been frustrated for centuries when they discover that the reason the students don’t understand a higher level concept is that they really don’t make the transition from one conceptual level to another. The problem is that learning is really not too much like stacking bricks, but more like wiring circuits. We have to make connections to learn. It is not enough to present material in an orderly and logical fashion, we must also make connections between different pieces of information. Every chance you get, you need to show how one piece of information connects to another. The more mental connections the students make, the more likely they are to remember the information. Students sometimes ask how a particular piece of information is relevant. I believe what they are trying to say is that they don’t have anything to tie the information to. Random, disconnected facts are quite difficult to remember, and are not normally particularly useful. I like the Bing commercials where people blurt out a series of largely unrelated facts that are essentially useless because there is no logical connection between them. To students, I am sure our lectures can sometimes sound like one of these commercials. I try to connect ideas together – showing how one part of a system affects the others, how pressure is related to temperature, how resistance is related to current – you get the picture. Relationships and connections between ideas are just as important as a carefully crafted sequence of information. This is not to suggest that building a foundation of information is wrong, I would just use the analogy of a framework instead. A framework can allow connections in more than one direction. Understanding a few fundamental physics concepts provides a framework for understanding both refrigeration and electricity. Taken by itself, physics can be pretty dry stuff until you realize that it describes the world around us. Once the students start making connections linking concepts together the whole process can go viral – they start finding their own connections and asking their own questions. This can be a bit scary because you no longer have total control of the flow of information or questions, but it produces an energized, lively class. More importantly, when the students start connecting concepts they are taking an active role in their learning and are far more likely to retain the information.

Budget Stretching Ideas

Schools face a serious budget crunch these days created by expanding enrollment and shrinking resources. There are many small things that you can do to stretch your budget and still provide a reasonable level of training for your students. Refurbishing tools that have become shop worn rather than replacing them is one small possible savings. Tools that normally last for years in the field sometimes only last a few semesters in our lab due to the harsh treatment they sometimes receive as well as the constant use. The seals and depressors in hoses are one example. If you have refrigeration hoses that leak, often the leak is in the seal on the end. The seal in most hoses is a small rubber tube that slips into the end of a brass cup in the end of the hose. The core depressor is either held in place by the seal or screws down into it. Replacement seals and depressors are available for most brands of hoses. If the hoses you have are used for connecting to refrigerant cylinders, vacuum pumps, or recovery machines, there is really no reason to have the core depressor. Removing it will speed up all those operations by removing a restriction. A larger savings can come in the type of brazing rod you keep. While I prefer 15% silver, it is now over $100 a pound and we use several pounds a semester. I hate to have students braze any less because brazing is one of those skills that must be practiced. 0% copper-phos is just over $10 a pound and does the same job. No, not as easily, but I can buy a semester’s worth for less than one pound of the 15% silver. Another savings for many programs is to reduce the paper you hand out. I have always been fairly liberal with the handouts, believing that it is important to disseminate information. I still believe that, but I have modified the way I share information. I started by writing a book that had more of what I wanted in it. But there will always be new information you run across that you want to share. Increasingly, I do this electronically by sharing web addresses. Finaly, let the supply houses and contractors in your area know you need help. They can keep their eye out for opportunities to help you. This past year we have received several donations from contractors and supply houses of “stale” stock or equipment with issues. They receive a tax deduction and we receive equipment. A unit with an issue may be a problem for a contractor, but it is an opportunity for my students . We have received two new packaged heat pumps this past year that had leaks on the pilot tubes of the reversing valves. Students patched the leaks and the valves worked. Now we have two new packaged heat pumps.  

Picture Perfect

Several years ago when I was a student in one of my education classes at the University of Georgia, the instructor asked us what should have been a fairly simple question for a group of teachers: “How do you know when learning has taken place?” I don’t remember my response, but I do remember that the question really brought me up short because it was not asking how do you know when the student has mastered a particular knowledge or skill, but how do you know when they have learned something? Well it is a little late, but I received a great answer today: Learning has taken place when the student requests that their picture be taken with their project. We have a flaring project in which students make an assembly of 1/4”, 3/8”, 1/2”, and 5/8” copper all connected together by flare fittings. After it is done, it is tested for leaks with 100 psig of nitrogen and soap bubbles. After completing their project, one student wanted a picture. Then they requested I take a picture of them holding the project. The student’s broad smile gave me the answer to the question posed to me many years ago. Learning has taken place when the student can enjoy the pride of achievement with tangible proof of their accomplishment. In technical education we have a huge advantage of being able to actually produce. The students’ pride is not based on my judgment, it is based on holding something they made that they could not make yesterday. Some people consider trade skills and knowledge as inferior to pursuits that are purely academic. However, I feel that a strong case can be made that technical skills are actually a higher form of learning because the students must actually perform. Reality is the harshest judge of all – either it works or it doesn’t. Our students must not only understand the theory, they must also apply it and pass the performance test. So if I had to list a learning sequence today, it would be: you study, you struggle, you sweat, you smile! 

Ride All the Rides

Summer is approaching quickly. Undoubtedly, many of you will spend some time at an amusement park, water park, or other recreational establishment. Many parks now have a single price for admission that lets you ride all the rides as many times as you like. After paying the price of admission, most folks try to ride as many rides as possible to get their money’s worth. I can remember planning out my day at Disney World so that I would make the most of my time. I can see many of you smiling because you have done the same thing and planned a manic day at a pricey amusement park so you would get your money’s worth. So here is my question. Why are we so intent on getting our money’s worth at an amusement park, but beg to be cheated in education? When you pay your tuition for the semester, you are paying to ride all the rides. Every lecture, lab, online assignment, and test is available for the price of admission. If you think tuition and fees are high, why would you not take full advantage of all that you paid for? Try reading the assignments more than once. It does not cost any more, and you get more out of the assignment. When you miss a lecture, lab, or assignment you are cheating yourself. Not only are you not taking advantage of the services you have paid for, but you are also limiting your earning potential later on. My brother Richard has a saying “work hard at school, or work harder all your life.” HVACR is a very performance based industry. If you can’t perform, you won’t last long. HVACR is also a very technical field. To excel, you need to understand the systems and how they operate. Sure, without a lot of training you can get a job holding the other end of heavy things or running to get tools for other people. But without training or education, you won’t advance much past that point. There are many ways to educate yourself, but the easiest and fastest is to go to school. Throw yourself into your studies. Attend all the lectures, read all the assignments, and do all the labs. Ride all the rides!

The Hunt

I had a conversation with a local contractor today who told me some of the things that impressed him about different job candidates. I thought I would pass a few of his comments along in hopes that it might help some of you out pounding the pavement looking for a job. First and foremost, remember that employers hire you based on what you can do for them. They are not philanthropists. With that in mind, spend a little time thinking about what you have to offer an organization so you will be prepared to answer when asked. Try and learn something about the companies you apply to. If you get an interview, you definitely need to learn whatever you can about the company. If they advertise that their employees are NATE Certified, stress your qualifications. Even if you are not yet NATE Certified, graduating from a respected program or passing the ICE exam is a good step in the right direction. Tom (not his real name) is a successful local contractor. He told me a few things he pays attention to. One was persistence and follow through. If someone comes by just once, he figures they are not really interested. He is impressed by students who return a few days after completing an application to inquire. Appearance is huge. Another contractor told me that the way an applicant looks to him is how he assumes they will look to his customers. You need to be clean and neat. Tom told me he remembered one student’s shoes – how shiny they were. The second time he came, his shoes were just as shiny. He got the job. He showed persistence and was consistently neat and clean in appearance. Do not wear a shirt with a slogan, witty comment, or add. You can never know what the interviewer will read into it, but why take a chance on creating a bad impression? It is also important to be dressed appropriately. Don’t show up in a three piece suit to apply for a job as a service technician. They may assume you are afraid to get dirty. It also helps to know your stuff. A student recently applied for a job and they gave him a test. He told me he knew he did terrible and wished he had studied before going to the interview. Later when I inquired, the contractor told me they had never had anyone score as high as he did. He got the job. More contractors are administering their own in-house tests. Don’t be surprised if they ask you to take a test. If you have studied HVACR at school, tests are your best friend – they give you a competitive advantage. Last, you need to have an upbeat, positive, can-do attitude. Remember, people often hire people they can get along with. After all, they are going to be around you a lot. Do not put down your previous employer. What the interviewer hears is you are a whiner and complainer. Do not put down your school, fellow students, or the instructors. If you successfully convince the interviewer that the school you attended is bogus, then why should they be talking to you? Definitely do not offer any current political or religious inspiration. I had a student lose a job over a comment about Ronald Reagan. Tell your beer drinking buddies what an idiot the president is, not your employer. Finally, when preparing for applications and interviews, think about who you would hire, then be that person. 

Dr. William Lipscomb

I heard on the radio that Dr. William Lipscomb had recently passed away at the age of 91. I confess that I really had no idea who he was. I became a little more interested when the announcer reported that he taught chemistry t Harvard and had won the Nobel Prize for chemistry. There aren’t many people that have done that. Then I became really interested when they said three of his former students had also won Nobel prizes. To me, that is really a much greater achievement. The mark of a good teacher is not what he has done, but what his students have done. He accomplished more by being a great teacher than he could have possibly done individually. I had to Google him to learn more. When I did, I found out that he was a student of another famous Nobel prize winning teacher – Linus Pauling. One of the quotes attributed to Dr. Lipscomb was “For me, the creative process, first of all, requires a good nine hours of sleep a night. Second, it must not be pushed by the need to produce practical applications.” I love this guy and I never met him. Here is a Nobel prize winning Harvard professor saying he is motivated by a need for practical application. This week’s posting is dedicated to celebrating the life of a great teacher, Dr. William Lipscomb.