Scientific Method and Critical Thinking



ok ladies and gentlemen the powers that be at Humboldt State University and our general education department have decreed that thou shalt learn about science and the scientific method and that's why maybe you're taking this class and so let's just address this right up front take care of it line it up and knock it down here we have a picture of a bunch of interesting people all of whom are scientists and oh you don't have to know them but if you're interested in doing a little research they all have very interesting stories behind them I'm just gonna point out to one Beatrix Potter now you probably know her from the Beatrix Potter books who were they they were the Peter Rabbit in Farmer McGregor two characters I remember in The Tale of Benjamin bunny well she was a children's illustrator but she is also a botanist a really good botanist she studied lichens and other small plants and but she was barred from presenting them because of the patriarchal discrimination of her time but if you look at her book she actually has lots of good scientific illustrations mixed in the other person I wanted to point out down here I'm being arrested it is James Hansen who is a very fine scientists scientist who worked for NASA doing atmospheric science and he worked for a government he's really got a long distinguished career and becoming concerned about carbon dioxide emissions and its effect on climate he was inspired to take direct political action which I think is a really interesting thing for a science scientist to do scientists try to be unbiased in their professional lives but acting as a private citizen I of course we're biased and and we're allowed to take action and here's a cool song if you'd really want have a funny song about that just that just google it and listen to it so what are we gonna do here here's what I want you to learn in this presentation and before I go on let me just say this presentation is a little bit long for an online presentation I don't know how long it's going to take maybe 30 min or so and the specialists who I talked to say that students can't concentrate for more than 15 minutes and I don't know if that's true or not but regardless if you feel your attention is wavering you have the control hit the pause button get up walk around and come back and finish it whenever you like so make sure you pay attention and you get this stuff in this lecture it's important so here's what I want you to get out of today's talk a definition of the term science to be able to distinguish the word science from technology to understand how we come to believe what we know assuming that science has something to do with knowing stuff how do we come to believe what we know that'll make sense as we get to it understand the assumptions behind the scientific method there are some and understand the components of critical thinking critical thinking a term you may have come up part upon in your education we think it's important that students learn critical thinking skills well what are they they are certainly applied in the scientific method so you might as well know what they are know the basic steps in the scientific method what happens after the experiment is completed and I want to give you some of the social context of science and I think that's particularly interesting to a number of members of this class who are social social workers people who are studying sociology and psychology sign you are scientist you're practicing science and you're interested in social interactions and so I thought this would be interesting by the way many scientists don't really pay much attention to this but I think it's important to raise and think about okay so first let's define science first of all to two aspects of science one it is a systematic method for learning about the world and testing our understanding of it so the main thing here is the word method this a systematic method and you probably already know most of it it's often taught in the grade school level certainly at the high school level and again and again and maybe in every science class that's ever taught but let's just make sure you got it down pat and furthermore science is also the body of knowledge itself derived from the method of the type that can be rationally explained and reliably applied so the body of knowledge so I've put in a pyramid here the pyramid of science and every little brick here represents a an experimental a scientific method in use that we yielded a publication and so there's been lots and lots of scientists doing work and all the new stuff on top relies on all the stuff that comes before so this is the body of knowledge and every little brick in it represents the systematic method that was applied in science okay two parts a method in the body of knowledge itself make sure you got that let's address the difference between science and technology because I think in the press and in common usage the two are commonly confused they are not the same thing number one science is as I have already defined the method and the body of knowledge derived from the method and technology is then the tools and techniques used to solve a problem so they're not the same thing do not confuse them science sometimes sirs technology very frequently let's say we need to make a better bandsaw maybe someone has an idea that if they include a different alloy the bandsaw saw will be better they will apply the scientific method to test their hypothesis that this new alloy will work and through experimentation they will determine how to make a better BAM saw the reverse is also true that technology serves science an example as well a couple hundred years ago we didn't have very good microscopes we had light microscopes made from glasses and lenses and metal but we then discovered electricity and we discovered how to use the electron electron microscopy and that is an example of technology and now that we have really good microscopes we can actually see viruses even molecules even Adams's things we couldn't do before so in this case clearly science has served science so you can see why they sometimes get confused but I want you to be sure you know the difference okay I wanted to talk about how science is used because it's important socially there are two general categories of how science used number one is it's used simply to satisfy our curiosity how does the world work the the cosmos the origin of the universe those questions are addressed through the scientific method I don't maybe maybe they don't have any practical application but it's really interesting to think where did the universe come from and to apply the scientific method to answer that so simple curiosity number two to develop something useful so some examples of how science can be used to develop something useful an antibiotic so we have these diseases Staphylococcus aureus tuberculosis whatever that is can we find antibiotics to cure diseases clearly that's useful reducing human suffering how about a better I pad a better tablet display we could use science to test new parts of tablets and improve the display make it last longer make it brighter better colors make it touch sensitive eye so that really I would say would be an example of commercial interest so science can be used to make more profits to stay competitive so that's not necessarily to improve human welfare but to make money maybe they're linked maybe not thirdly how about a better kind of weapon and you can be sure that we spend a lot of money using science to develop better weaponry there's always gonna be arms races for whatever reason and so I think it's important to acknowledge that a large part of the United States budget goes to fund the military and a big fun wedge of that goes to support research to improve our military capability okay so today what are some of the main uses of Science and Technology medicine military as already mentioned corporate profits already mentioned these human welfare and then lastly people who are interested in just basic science like what about those fungi on tree roots what are they actually doing and these are not always easily related to human welfare corporate profits military or medicine but they expand our understanding of the world sometimes they have great spin-off and then sometimes they don't and yet we are enriched in my humble opinion in and that kind of information I want to reveal my bias here this is the part of science I am actually most interested in I'm not so interested in developing antibiotics better tablet displays better bombs and medicines I'm really interested in bugs and creatures that's my personal bias but other people do things for other reasons I just wanted to give you some of a sense of the breadth of how science and technology are used so changing subjects and by the way if you feel tired and you're losing your concentration now is a good time to take a break pause button get up walk around and come on back but right now what I want to do is to address a sort of deeper question how we come to believe what we think is true we may never really know the truth but we think we know the truth we believe we know the truth well how did we come to believe that we sort of take that for granted sometimes and even in the scientific realm of course we think well science tells us it's true so it must be true well let's take a close look at that I've come up with a list of several ways we come to believe what we think is true one is by faith complete trust or confidence in someone or something if science has told me that all life is composed of living cells well maybe I believe that that is true because I have faith in that I have complete trust your confidence in a person or a book or something like that so just through faith through personal experience maybe every time I get that rash its fall and so I believe that Falls cause rash I don't know anyway you know personal experience is very strong and it's really hard to make someone disbelieve something from their personal experience even if the personal experience might be just coincidental and there's not truly cause and effect Authority and we do this a lot there's many sources of authority it begins with our parents when we're babies our parents tell us this that or the other thing and we believe them or it may be that you take a class and your teacher assigns you a textbook and this is big fat $200 textbook the book itself can become an authority the Bible is an authority to many people the Quran the Quran so we often believe what the authorities the people or sources of information we invest with Authority we believe that whatever they say is true without really critically thinking about it maybe that could be a person a group of people are convincing book or what about the internet well that's kind of a loaded question we'll talk about Wikipedia later on in this course sometimes we just logic our way to something without any personal experience without anybody telling us without any faith in something we just logic our way to a conclusion and come to think of it as true watched Sherlock Holmes sometimes he's really good at that and if you want a humorous application of that Google the she's a witch scene from Monty Python and the Holy Grail and there's a really funny misapplication of logic there and then so let's take a look at experimentation experimentation is really a mixture of logic of authority and personal experience let's start with personal experience you set up the experiment to begin with because maybe you've had some personal experience with something that leads you to a hypothesis maybe you've done your research and you've consulted the local authorities or the authorities on the subject area you're interested in and then you design an experiment based upon that information and of course you apply logic and setting up your experimentation so experimentation is a mixture of all these things it is a way to figure out what is true there are many ways to come to believe what we think is true I just wanted to say that science is only one way of coming to understand the truth there are other ways but I want to emphasize that science is a very powerful way of coming to an understanding of truth through the application of the scientific method we have discovered antibiotics that have cured us of diseases vaccinations that have eradicated for instance smallpox and we've also developed very terrible things such as nuclear weapons and who knows maybe even the whole industrial revolution is a terrible thing but it was derived from science so it's extremely powerful and that's why it shows up in your general education curriculum has something important to learn about it does have some assumptions that underlie it and there are three of them and I think it's important to consider them number one the universe works according to unchanging natural laws well that's pretty cool scientists are famous in coming up with laws like thermodynamic laws or gravitational theory and the assumption behind these things is that these are unchanging if we have agreed to call something a natural law then we assume that it has been in place since the beginning of the universe at least and has unchanged since then if that's not the case a lot of our science falls apart so that's interesting to think about number two events arise from causes and they cause other events in other words there is cause and effect in the world so for instance a scientist goes out and sees peacocks and notices that the peacocks the males have these ridiculously colorful displays huge feathers that make it really hard for them to fly and get around and actually make them pretty easy prey for predators maybe but the females don't have those things why is that that question why is that is based upon an assumption that there the universe exists with cause-and-effect things don't just happen that there if there is something funny going on there must be a cause and so scientists are always looking for the cause of observed effects and lastly we can understand natural processes by using our senses and reason by looking and recording and using logic to try to figure out what's going on now it's possible that we can't maybe there's things that we cannot observe or that don't apply that we're the rules of logic don't apply not quite sure where those would be because we can't see them and maybe some of our ideas sort of bump into our limits of our ability to sense things for instance maybe you've heard of string theory string theory that posits multi versus multiple universes and multiple dimensions and since we don't have senses that can perceive these things maybe we just can't come to understand them but we try the best we can and these are the three assumptions of a scientific method this is a good time to take a break if you want to because you really should focus and concentrate on this next part critical thinking permeates the academic curriculum our teachers the professors in college really want students to use critical thinking and yet we don't often define it for you so it's kind of hard to do it if you don't know what it is I thought it might be useful just to lay it out what is this thing called critical thinking well I'm sorry if you do some research on it you'll find that there's many different approaches to critical thinking and I've just come up with my approach and maybe you'll find it differently somewhere else but at least this is a good starting point and I'm just listed some components of good critical thinking first seeing both sides of an issue in other words not being close-minded being close-minded and not seeing the other side of an issue is bad is not critical thinking so we like our students to question things that is how we can move forward by questioning our assumptions every now and then we find out one is wrong and when we do that we learn something new we open up the door to new learning number two being open to new evidence that contradicts your ideas I am really amazed some times in my students who I will set up a lab experiment and they'll get results and they will report what they think we should have gotten instead of reporting what we really did get ah so you're really often critical thinking involves just looking at what's in front of you and using logic to come to a conclusion regardless of what your pre-existing ideas are apparently that is really difficult for people to be open to new evidence that contradicts your ideas but that's an important component of critical thinking reasoning dispassionately basically I think what that means is being logical and not emotional and so there is no role it for emotion in the scientific process now we're emotional creatures and so in a way you might say that's impossible but basically we try as much as we can to remove passion from our practice passion and what I mean by that is not excitement but emotion positive or negative just for instance I'll give you an example of a failure of this among some scientists I've heard of there was a dispute between two scientists they both published papers at contra at each other and in public they were swearing at each other they were being very passionate they were not using reason to address their differences so we try it we sometimes fail but that's one component of critical thinking if someone comes into you trying to convince you of something using very emotional language they are not being critical thinking they're not being scientific I would frankly as a scientist I would distrust them forth demanding that claims be backed by evidence if someone tries to make a claim for instance that wearing copper bracelets will reduce your rheumatoid arthritis I would say what is your evidence for that and I would look at that evidence very carefully that would be critical thinking not just assuming that what they say is true because it's groovy or because someone else says it's true or whatever evidence forth deducing and inferring conclusions based on available facts that is being logical deduction and inference or parts of logic so critical thinking is logic based upon available facts so that's that gets back to the evidence part so that's five steps five steps of critical thinking make sure you study those they might show up on examinations with your weekly exams and in fact they probably will and there you go critical thinking I just want to say though I was doing some reading about this and I found someone who said that critical thinking is hard to teach unless students have domain knowledge this is a bit of a side you don't have to know this for me but basically how can you apply critical thinking in these five ways to something you basically don't know anything about if you know an awful lot about say nematodes in their environments then you can use critical thinking when someone makes a claim about nematodes but if you don't know anything about nematodes or copper and rheumatoid arthritis then it's gonna be very hard for you to use critical thinking but the more you know about a subject area the better you are able to use critical thinking to advance it so expertise counts I think that's the bottom line here okay another time for break if you're feeling a little tired because we're changing the subject in getting to something very central to our general education what is this thing you call the scientific method and here I present the steps in the scientific method which you may have had in grade school and high school and I hope you did and I'll go through it pretty quickly number one observe question and consider possible answers this is the very beginning the most creative part of a scientific method you observe nature you ask it a question why are those peacock so colorful why are all male bird species and many other animal species the male often is really fancy and the female is not so fancy you observe you ask the question and you consider possible answers then you develop a testable hypothesis for instance I believe that I am I hypothesize that peacocks and other birds are fancy to attract mates is that testable yes it is I won't go into some of the possible tests because that's the third part you need to develop a replicable experiment to test the hypothesis so I want to focus on that term replicable what does that mean it doesn't mean you will replicate your experiment it doesn't mean that you will do it more than once but it means that somebody else who wants to do your experiment could do it it can't be one and done and no one else can do it because then no one can check you replicability means that somebody else can check your work very important I a couple decades ago someone thought they discovered cold fusion that is they could generate massive amounts of electricity without intense heat well it turned out that their experiment wasn't really replicable and it was discredited subsequently so that was important all right so you have designed an experiment you perform it and gather the data number for it just really unbiased very very logical just actually no logic involved just do what you said you're gonna do and collect the data once you have the data it's time to look at it analyze the data form conclusions form conclusions about the hypothesis was I did my data support my idea about peacocks or not and if so good if not then hmm maybe I need to suggest some future work in this area okay so that's the last part of the scientific method sort of there is another extremely important part that is o of often overlooked it must be published very often people do experiments I do them at home but I don't publish them so it's not really part of that pyramid of science until it gets published now where we critical thinking be applied here it would be applied throughout you would be using logic and observation and trying to avoid passionate pleas for one solution or another you would be very logical about how you analyze the data and so forth so critical thinking is used throughout the use of the scientific method but that's how it's usually presented this yellow box this is the scientific method I'm sure you've seen it before I am gonna take this a step farther because it is so important because once well let me go this way so after you get your results you write your paper and you publish it but how what is the process by which it is published you write it up and you submit it for publication to some reputable journal and what happens is that photocopies of it are made and they are sent off to other people who read it and they judge it they look at it is it logical does the experiment adequately test the hypothesis did they come to justifiable conclusions is it interesting and if it fails at any of these it will be rejected and this person will go back and cry because you spent a lot of time doing this stuff or maybe they'll revise it and try it again and it'll go through that process again very often papers go through several rounds before they're finally accepted and published but that's not the end of it publication is not the end of it there are gazillions of papers that have been published and then just language they're never that languish they're never noticed and so very often a scientist will not just publish a paper but also go to conferences and present posters and and try to make other people pay attention if a paper is accepted and it gets a lot of attention then that is really good for the person who publishes it in many different ways it makes them more popular it makes a lot of people know their name it helps them hire graduate students it helps them get money to support their future research and their professional position this is a social context in which science operates and it's important to understand we try a scientist to remain very objective but sometimes it does not it goes beyond objectivity and there's self-promotion and there's there's enemies and friends and it becomes all very dramatic just as in any other social context so to ignore that fact is to to really do science a disservice so it happens and science sometimes slips behind when people cheat and don't do things right but we do the best we can to remain unbiased and objective and it limps forward and actually it flies forward progress of science just flies forward okay and we do all that stuff and the material on these two slides basically you don't and I'm not gonna test you on it but I want you to pause this presentation stop listening to me read through this stuff and meet me at the end of the presentation and also have some things to say so go ahead and pause and read one two three pause okay you're back I am pause it again and read all this stuff you don't have to memorize this stuff just read through it ready pause and then come back okay here we go okay so I just wanted to write all that other stuff to give you again a sense of the social context of the scientific method and it is so important to me I think that I have actually designed one quarter of your grade to be an exercise in the scientific method and your next presentation on our Moodle site will explain what that is but essentially what you'll be doing is forming a hypothesis testing it running the experiment gathering the data and writing it up in a paper for this class just as in that yellow box but you will try to publish it in this class by submitting it and you will be submitting it to a group of students who will read your paper and you will be reading other students papers and judging their merit and looking for ways that it can improve and returning those papers and you will get your paper back and you'll revise it and you will improve it and you'll submit a final draft of your paper and it too will be submitted to a group of students who will judge it relative to other papers and there will be winners and losers just as happens in the real scientific world okay all the details of that are forthcoming but I hope you participate in it you try to do the best job you can and I actually hope you have some fun doing it and that concludes this lecture this picture is a picture of a lake in Keela Toa crater which is the westernmost volcanic crater in Ecuador and a source of deep beauty okay BC Nia at the next presentation take care

2 thoughts on “Scientific Method and Critical Thinking”

  1. I like science, is study statistic a good option I not particular in studying a partcular branch of science but I like the scientific method.Do u think is a good option statistics ? Thanks

  2. Dear Prof Jack,
    I have been browsing through a lot of videos on this topic and haven't really benefited from those because most of them were babbling and you have made the points really clearly! thank you

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