Intro to Astronomy Assignment

Lab Lecture—Getting Started

This week, you'll do the first of your lab assignments in this class. There's a lot of information about these labs in the lessons (an introduction to the labs in the Week 1 lesson, and instructions for each individual lab in the appropriate week's lesson). In my experience, there are a lot of questions that come up about the labs that are answered in one of these places, but these labs are a new experience. So, I wanted to explain some things face-to-face (as it were) in the hope that it will help you. A full transcript is located just below where you clicked on this.

These labs were specially designed by astronomy education researchers to help students learn about how science is done. Too often, lab assignments are what we sometimes refer to as "cookbook labs," where students are told specific steps to do in order to arrive at a specific answer. But that's not really how science works. Science is really about looking at the world around us and asking questions. We then think about what kind of data we would need to collect in order to try to answer our questions. Once we collect that data, we analyze the data to find evidence that can be used to answer the question. We use that evidence to come to a conclusion (which is, therefore, called an evidence-based conclusion). That process is what I'd like you to experience in the labs this semester.

Lab Lecture—Difference Between Data and Evidence

What is the difference between "data" and "evidence"? It is very important in science to get our vocabulary straight, so that we can communicate clearly. Let's start with the dictionary definitions. According to the Merriam Webster Dictionary, data is "factual information (as measurements or statistics) used as a basis for reasoning, discussion, or calculation." Evidence is "something that furnishes proof." So, when you're conducting a science experiment, data is the group of measurements that you collect, but evidence is those pieces of your collected data that you determine to be relevant to your research question. For example, let's say that your research question is "How does temperature fluctuate throughout the day on a particular Monday at your location?" You would look at your outdoor thermometer, say once an hour throughout the day, and note the temperature. Those measurements are your data, and you can use that data as evidence to answer your question. Let's say that your thermometer also has a humidity display, and you were to also note the humidity measurements in your notes. Those measurements would also be data, but they would not be evidence for your research question, because they are not relevant to your question about temperature fluctuations. Similarly, if you noted the temperature on Tuesday, that would also be data, but not evidence, because your question only asks about Monday, and a Tuesday measurement is therefore not relevant. In addition, if you were to measure the height of the thermometer above the ground, that measurement would also not be evidence, as it is totally not relevant. So, to sum up, all data isn't evidence, but all evidence is data. Specifically, evidence is the relevant data.

Lab Lecture—Phase I

OK, so back to the topic of the labs. For each lab, you will start in the page in that week's lesson. First, download the lab document itself. It's a Word document, and you should enter your work directly in that document. Please name the document with your name and the lab number. Next, read the instructions that are on the rest of the lesson page, as there is some clarifying information there. Then, move on to the lab document, and work through from top to bottom. It is very important that you don't go out of order, as the labs are carefully structured to support your learning process. Each lab has six phases, and the process you will be doing in each phase matches from lab to lab. You're not just being thrown into the fire on these labs. Each phase guides you through the process of scientific inquiry.

In phase I, you will be guided through exploring a particular set of data that is available on the web. For example, in lab 1, you will be looking at an amazing image of galaxies called the Hubble Ultra Deep Field. Don't worry, you aren't expected to know anything about galaxies yet. This is the first lab for a very specific reason. You won't be learning about galaxies until much later in this class, and I want you to be able to approach this lab without your mind cluttered up by those details. I want you to learn to look just at what is in front of you. In later labs, you'll be looking at different types of data, but in all of them, you'll use phase I to play around and learn about how to use the website for that lab. Phase I is the part of the lab that is kind of like a traditional "cookbook"-style lab, where you're told what to click and do, so that you can answer specific questions. When the lab talks about stars in the image having "four points," this is an example of that. Stars don't really have points like that, of course, but since the telescope was focused on this part of the sky for so long to take this image of incredibly distant galaxies, the nearby stars in our own galaxy got overexposed.

Lab Lecture—Phase II

In phase II, you're going to be shown how to collect some data from the site. In the case of lab 1, you're going to be asked to make rough sketches. You can either use a computer program to sketch, or you can do it by hand on paper. You can then scan or photograph it, and either insert it into the Word document, or upload it separately when you submit your assignment. "Rough sketches" means just what it says. This is not art class, and I don't care whether you think you're a good artist or not. Just show me a representation of what you see to the best of your ability.

You're then given a generalization (which is another word for conclusion for our purposes) that some hypothetical student came up with. You're asked whether you agree or disagree based on the evidence you collected (your rough sketches). It doesn't matter whether your answer is "right" or not, you're being asked whether that conclusion matches YOUR evidence. Make sure to specifically explain what it is about your evidence that leads you to agree or disagree with the student's generalization.

Lab Lecture—Phase III

Now on to phase III. In this phase, you are given a research question (What is the general distribution of galaxy colors?) and this time you are provided with a set of data. Use this data to find relevant evidence to come to an evidence-based conclusion about that question. Be specific in explaining your reasoning, and if you want, you can use sketches, pie charts, or graphs to support your reasoning. Don't use any outside information here. Base your conclusion only on what the data you see in front of you says. This phase is helping you to learn that evidence-based conclusion need to specifically answer the research question, and must follow from the data.

Lab Lecture—Phase IV

In Phase IV, you're given a new research question (Are there more nearby galaxies or extremely distant galaxies?). Note that way back in phase I (question 4) we make an assumption that's very important here. We assume that all of the galaxies in the image have the same diameter, so therefore the ones that are close appear larger, and the ones that are more distant appear smaller (examples in video). While this assumption is not strictly true (again, you'll learn much more about galaxies towards the end of the class), it is a safe assumption for our purposes here. In this phase, I want you to think about what data is necessary to collect from the Hubble Ultra Deep Field to be able to answer this question. I do NOT want you to bring in any outside information. You don't need your textbook, the internet, or anything else, just the website you're using to view this one image. Now, write out a detailed, step-by-step description of what data you need to collect and how you would go about doing it. Pretend that someone else, who is unfamiliar with this website, is going to pick up your directions and follow them to actually collect the data. You might want to include a blank table to show that person how to record their data. You do not need to collect the data yourself. This phase is just about practicing writing specific instructions to do so. In science, this is really important, as good science results need to be repeatable. Someone else needs to be able to follow the same procedures and get similar results.

Lab Lecture—Phase V (Including Tips for Asking Good Research Questions)

OK, so at this point in the lab, you have been introduced to several characteristics of galaxies that you can determine by looking at the Hubble Ultra Deep Field. We've got color (mainly red-orange, white, and blue (video shows examples)), we've got shape (mainly circular-round and elongated spiral (examples in video)), and distance (which we assume from the relative size of the galaxies on this image, with the galaxies that appear large being nearby, and the more distant ones looking small). You have also seen several examples of questions that can be asked about these characteristics (either alone or in combination). For example, in phase II, we examined the shape of nearby galaxies. In phase III, we looked at the general distribution of galaxy color. And in phase IV, we looked at relative distance.

In phase V, which is the most important part of this lab, you will synthesize everything you've learned up to this point, and I let you loose to conduct astronomical inquiry on your own. Sound scary? Take a deep breath. I know this is the hardest part of the assignment for many students. In fact, research has shown this to be the case, which is why the labs are designed to guide you through this process carefully, leaving this hardest part to the end, even though asking a question is the beginning of the process of inquiry. You've seen this process of inquiry a few times now in this lab, you've been led through the process, and now you're going to try your hand at it.

I want you to ask your own answerable research question. Don't worry, the question does not need to be complex or sophisticated, but it does need to be answerable, by you, using this image. Do not try to ask a question that you can't answer using this image. Do not ask "why" questions, as those are not answerable using this image. Do not ask questions about galaxies that don't relate to the three characteristics we're talking about in this lab (color, shape, distance). In other words, this is not the place to ask why galaxies were formed out of the Big Bang (that's a great question, but not for an introductory astronomy lab, as professional astronomers have been working for the last century to ask it, ever since they realized what galaxies are). Here are some tips about asking good research questions.

1) Go ahead and ask what you think might be an "easy" question, at least in the early labs. You don't have to win a Nobel prize with this question.

2) Don't ask too complicated of a question with several variables because you also need to actually take the data and come up with a conclusion. Don't make this harder than it needs to be.

3) On the other hand, don't ask something trivial, such as something that could be answered with a simple "yes" or "no." For example, a poor research question would be, "What shape and color is the large galaxy in the bottom right corner of the image?"

4) Some good questions might compare two things (or, in later labs, you might be able to ask about how something changes over time, but that doesn't apply to lab 1). You might want to ask about one particular characteristic (color, shape, or distance) in relation to another one.

5) Look at the questions asked in the previous phases of the lab you are working on. Usually, you will have three different examples of good research questions and maybe you can change one of them a little bit to come up with a new research question.

6) Be sure you use the website that is used throughout the rest of the exercise to take the data, and don't come up with a question from out of left field. Since we're talking about galaxy characteristics, don't ask about individual stars, for example.

Once you have your question, you're going to write out a step-by-step procedure to collect the data you need (just like you did in Phase IV). Only this time, you're actually going to follow your steps and do the data collection. Record your data in a table or whatever is appropriate for what you've decided to collect.

The last step in phase V is to write your evidence-based conclusion. Look at your data, decide what is relevant (that's your evidence), and write your conclusion, explaining your reasoning (how you used your evidence to come to that conclusion).

Lab Lecture—Phase VI and Getting Help

Finally, you will write a summary in phase VI (definitely don't skip this, as I want to get an idea for what you learned). Write only about the information you learned by performing the exercise and how that ties in with what you know. Don't go to your textbook, Wikipedia or another website and do an information dump of facts on the subject.

If you get stuck, post a question to the Lab Q&A Forum or message me directly for help. One of my least favorite things is to get a blank lab that just says "I didn't understand how to do this." You are in college to learn, but you are NOT in this alone. I am here to guide you through your learning, but I can't help if you don't ask and tell me what you need.

Good luck, and have fun with this!