Doing Science AP Biology

What have we already said about science? Science is a way of finding answers to questions that NO ONE knows the answer to. NO looking it up in a book NO asking someone So how do you know if you are right?? Maybe you don’t for a very long time…or ever.

Can Science answer ALL questions? NO Science can only answer questions about the NATURAL (meaning PHYSICAL) world / universe in which we live NOT moral / ethical questions Science cannot tell us if something is right or wrong NOT questions regarding the supernatural The supernatural, by definition is NOT bound by the laws of nature FALSIFABLE Hypotheses cannot be made regarding the supernatural Science cannot tell us if there is a God, if ghosts exist, etc. because these entities are not limited by the laws of nature

So what can science do? Science can help us answer questions about our natural world It does this by giving us a set of tools and a framework to methodically seek information Observation Experimentation Often in a flexible framework we call the SCIENTIFIC METHOD

Scientific Method A FLEXIBLE series of steps Observe a problem Form a question regarding this problem Form a hypothesis Research to see if your question has already been answered Design an experiment IV, DV, constants, control Determine data collection methods; analysis that will be done Carry out the experiment and collect data Analyze data Draw conclusion Share findings At ANY point, re-evaluation and even a complete overhaul of the process is possible!

Observe a problem CAREFULLY observe The Box O’ Science

Form a Question regarding the problem… How the heck does it do that? More fluid out than in Fluid out is different color than what went in

Form a Hypothesis regarding the question An educated guess as to a possible explanation or answer to the question… How can you explain your observations regarding the Box???

The Importance of a Testable Hypothesis Hypothesis – a tentative answer to some question Having a TESTABLE hypothesis is critical to carrying out the scientific method. Having a hypothesis that is actually testable by the scientific method LIMITS the kinds of questions the scientific method can answer. “Scott falls asleep in class because the ‘devil makes him do it’” is not a testable hypothesis.

Other Important Points Regarding Hypotheses Hypotheses are possible explanations for some phenomenon. Never just a statement or observation. Must seek to explain WHY something is happening. Hypotheses reflect past experience In other words, hypotheses should seem reasonable…at least this is where hypotheses should start. Multiple hypotheses should be proposed whenever possible This helps a scientist avoid “favoring” a particular outcome in an experiment. Again, Hypotheses should be TESTABLE. Hypotheses can be eliminated but NOT confirmed or “proven” with absolute certainty. Even the most thoroughly tested hypotheses are accepted only conditionally , pending further investigation.

Research Well…you could research it, BUT This means you will have to… Not likely to find anything about “coleman’s Box O’ Science” in the library or on Google… Could ASK others, BUT…ALL students who know the secret have GRADUATED AND they have been SWORN to SECRECY Their ears will fall off if they tell. It will be very obvious. This means you will have to…

Design an experiment to test your hypothesis In actuality there are LOTS of ways to test hypotheses or answer questions that do not necessarily involve a controlled experiment Observation of wildlife; simply watching and recording have told us volumes… Making models…when the system is too big to do an experiment with (for example, Earth’s Climate) then computer models are the next best thing…

Biologists use forms of inquiry to explore life Two main processes of scientific inquiry Discovery Science Observation based Hypothesis-based Science Controlled experiment based

Controlled Experiments Subjects are divided into two groups Experimental Control The two groups should be treated exactly alike EXCEPT for the ONE variable the experiment is designed to test This provides a basis for comparison

Designing a Controlled Experiment This is the textbook stuff you need to know… Independent Variable The thing you manipulate Dependent Variable The thing you measure Control Treatment A set-up of the experiment that does NOT get the independent variable It’s “NORMAL” STANDARD OF COMPARISON Experimental Treatment(s) The set-up of the experiment that gets the independent variable…maybe several different set-ups receive several different versions of the IV Constants Everything that is NOT the IV must be held the SAME between all treatments Multiple Trials Repititons of the experiment Do NOT reduce errors in the experiment, but LIMIT the EFFECTS of errors on DATA

Also… Designing the experiment should include Anticipating what type of data you will collect and HOW you will collect it Data tables made, etc. beforehand What TYPES of data will be collected Qualitative descriptive Quantitative numerical Anticipating how you will ANALYZE this data when the time comes

Run Experiment and Collect Data Pretty self-explanatory

Analyze Data Run statistical Analyses Graphically display data

Draw Conclusions Was your hypothesis supported by the results of the experiment? What evidence leads you to this conclusion? Note that the question is NOT “was your hypothesis PROVEN?”!! Were there things about the experiment that should be improved upon? Are there other questions that should be asked based on these results?

So…I supported my hypothesis! Do I have a Theory? No. What is a Theory? In Common language A guess; opinion In science Broad in scope Spawns many hypotheses that can be tested Supported by a massive body of evidence Explain a great diversity of observations Theories can also be modified and adjusted as new evidence comes to light A BIG DEAL

Science as Process Science is simply a way of knowing. Remember, it is not the only way of knowing. It seeks to answer questions about the natural world Science operates under the premise that questions about the natural world are answerable by making observations of the natural world and that the events observable in nature can be explained in terms of natural laws. The supernatural is BEYOND the realm of scientific discussion because the supernatural is not bound by the laws of the natural world. Science has no means of studying something that is not bound by the laws of nature.

Science vs. Technology Science – gain knowledge Technology – use knowledge Society must determine appropriate uses of knowledge

Science is a Social Activity Not done in isolation Both Good and Bad

A Critical Problem in Today’s Science Spin Be aware that science, like any other type of information can be politicized by different groups seeking certain political/commercial outcomes. It is VERY difficult for even an educated person to tell the difference between “bad” science and “good” science. Bad science – experiments designed to support a desired result Good science – experiments designed to determine the answer to some question. Be aware of the sources of published research; from whom they receive funding, etc. Think about what the researcher (and funder of the research) has to gain or to lose from the results of the research. As you develop your ideas about all kinds of issues, do not just look for information to support the point of view you already hold. Look for information that tells you the truth. Admittedly, it is extremely difficult to tell the difference at times. AND it usually makes a simplistic black and white point of view a LOT harder to maintain – and most of us find this uncomfortable.

About Sharing Results Abstract Introduction Materials and Methods A brief summary of the experiment Introduction Background; why the experiment was done; relevant information about the subject Materials and Methods How you did it; procedures; NOT a list of steps, though Results What your data showed; statistical analysis; graphs Discussion What your data mean; hypothesis supported or rejected and why you think so; problems with experiment; further work that should/could be done References