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Day 2: The Scientific Method, Critical Thinking and searching wisely. Sravanthi Nalamalapu sravanthi .nala malapu@mail.wvu.edu January 14, 2014. Problem Solving. Problem solving is the process of analyzing and finding solutions for questions that we want to solve.
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Day 2:The Scientific Method, Critical Thinking and searching wisely Sravanthi Nalamalapusravanthi.nalamalapu@mail.wvu.edu January 14, 2014
Problem Solving • Problem solving is the process of analyzing and finding solutions for questions that we want to solve. • How do we perform problem solving? • One way is with the scientific method, the process by which scientists, collectively over time, endeavor to construct an accurate representation of the world.
Scientific Method • 4 major components • Observation • Hypothesis • Prediction • Experiment • 1 evaluation step • Decision
Scientific Method Process theory If everything is consistent, advance hypothesis into theory. Consistent observation hypothesis predictions Inconsistent, edit hypothesis If not consistent, modify predictions and test again. tests
Observation • Areas of interest in which one sets out to prove truth or faults. • What kind of observations can you think of? • The average temperature of the earth is rising. • Foreign-made cars have been gaining market share in the United States. • People from the southern US tend to be more tanned than those in the northern part of the US.
Observation In-Class Example • An example of an observation might be: • You work for a computer manufacturer. The latest model, the X900, is selling very well. • You wish to explore this observation and find out the reason for the strong sales.
Hypothesis • Suggested explanation of problem or observation • How do we get hypotheses? • From other branches of science • Informed guesses • Random ideas
Hypothesis In-Class Example • What hypotheses might explain the sales of the X900? • Looking at marketing data per year, the amount spent on Internet advertising appears to be higher the year this computer was introduced. • Hypothesis: the increased sales were the result of the increase in Internet advertising. • This computer was the first to use the latest graphics card, the Screamer 9200. • Hypothesis: the increased sales were the result of using the latest graphics card.
Prediction • Formal way to put a hypothesis to the test. • If the hypothesis is true, when x is manipulated, then yshould happen. • xis the independent variable: it's the thing changed. • yis the dependent variable: its value depends on x.
Prediction In-Class Example • What predictions could you make based on the data we have? • If a greater amount is spent on Internet advertising, computers will sell better. • Using the latest components will increase sales.
Experiment • Test hypothesis to see if it’s correct. • Lab experiment (grow cultures in petri dish) • Analyze current data using computer applications (Access, Excel) • First hypothesis may not be correct • If so, no problem: go back and change it • May not be possible to completely prove or disprove a hypothesis • Example: Can’t completely prove or disprove whether cell phones cause driving accidents • What do we do in that situation?
Experiment In-Class Example • What can we do with our data to test the hypotheses? • Graphics card hypothesis • Run a query on the components table. Group the data by graphics card type. Do the units sold tend to be higher for certain cards? • Export this data into Excel and graph it, with units sold on the y axis, and the component name on the x axis, for each component type. Is there a pattern? • Internet advertising hypothesis • Run different sorts, by each advertising type, then by year. Does there seem to be a pattern? • Export this data into Excel. Graph each expenditure type on the y axis, and the year on the x-axis. Fit a trendline to the data, and forecast it out a few years. Is a pattern visible now?
Decision • Reject or accept the prediction(s). • If the hypothesis appears correct, you can create a new hypothesis, and begin again. • Would this hypothesis apply to other, similar cases? • If it seems incorrect, reformulate and try again. • Remember correlation doesn’t equal causality! • When the sun rises, the sky gets light. Does sunrise cause a blue sky? Yes! • People who don’t wear seat belts tend to have worse accidents. Does one cause the other? Only partially! • Tall people usually weigh more. Does height cause weight? No! • In each case, though the first and second are related, it’s not necessarily true that one causes the other.
Decision In-Class Example • A sharp increase in the percentage of Internet advertising the year the X900 was introduced was the reason for its increase in sales. • Look at other computers introduced that year to get a better idea if this is correlation or causality. • The use of the Screamer 9200 was the reason for the X900’s success. • Again, correlation vs. causality: check out other computers that use the new card to see which one is the case.
Critical Thinking • Definitions: • The scientific method applied to life. • An attempt at objective judgment so as to determine both merits and faults. • The art of taking charge of your own mind!
Non-critical Thinking • Left to our own devices, our thinking often uses rigidity, over-generalization, prejudice, and common fallacies. • Voting a certain way because that's the way your parents did (or didn't!) • Buying a brand new car because it looked good on the lot. • Copying/pasting in Word using a mouse because that's the way you've always done it.
Why use it? • Objectively arriving at a decision (the purpose of critical thinking) has many benefits. • Cheaper (you’ll buy less frivolous/needlessly expensive things) • Healthier (more likely to exercise, spot doctor mistakes) • Better grades (critical thinking = better study habits!) • Higher pay (critical thinking is invaluable in finding and keeping a great job)
Critical Thinking in CS101 • Is there a faster way to do the task I’m doing than the way I already knew? • Shortcut keys, icons, etc. • How do I use Microsoft Office to answer the critical thinking questions? • Access: sorting/grouping with queries • Excel: graphing, scenarios, PivotTables • PowerPoint: organizing ideas effectively • Word: getting ideas down on paper makes them clearer
Critical Thinking in School • When studying, turn section titles into questions, and use that section’s text as a chance to answer that question • If the section is titled “Formatting Spreadsheets in Excel, ask yourself “How do I format spreadsheets?”, and look for the answers as you read. • Do extra review questions at the end of chapters. • At the end of each lecture, take one minute, and answer the following (try this now!) • What’s the most important thing I learned today? • What’s the thing I’m still most confused about?
Critical Thinking in Life • When trying to decide whether to buy something • Do I really want/need it? • Can I afford it? • Is it good (healthy, non-dangerous) for me? • When voting • Familiarize yourself with the issues. • Think about the long-term implications of your choice. • At the doctor • Ask questions. • Get a second opinion.
Finding Information • As you continue in your courses and eventual careers, you’ll find that you frequently will have to find information. • With the resources available through the Internet, it is easier than ever before to find large amounts of information. • This is a double-edged sword: it’s also easy to get buried under too much data. • It’s important to understand that just because the data is available doesn’t mean it is correct.
Search Engines:Planning Your Searches • To help find data quickly, plan your searches. • Be specific and use multiple keywords. • If you are searching for German shepherds in West Virginia, you will get better results using the terms German shepherd and West Virginia than if you just searched using the term dogs. • Try searching for different terms and synonyms. If car doesn’t work, try searching for automobile.
Search Engines:Fine-Tuning Your TERMS • Use phrases and quotation marks • “Springfield, Illinois” will return pages that reference only Springfield, Illinois with the words in that specific order. • Negative terms • Virus –computer will find pages that mention the word virus but not the word computer. • AND and OR queries • Most search engines automatically insert the word AND between phrases (which is why quotation marks are useful) so there is no need to type it in the search engine. OR is useful for searching for more than one term, such as West Virginia University OR WVU.
Search Engines:staying on-target • Google ignores common terms such as where and how, as well as single digits and letters. • It is not case sensitive. Typing aNoThEr pHrAse will return the same results as another phrase. • To search for Roman numerals or a common word, either use quotations or the + sign. “Star Wars I” and Star Wars +I will return about the same results. • Use the site command • football site:wvu.edu will return pages that reference football, but only on WVU servers.
Search Engines:Getting Additional Help • Try using Google’s help features. • The search engine’s help page can be found at http://google.com/help/basics.html and from there, more advanced search tips are available. • Most other search engines work similarly to Google.
Wikipedia • Wikipedia is a free user-edited online encyclopedia at http://en.wikipedia.org • Advantages • Huge volume of information, often on subjects not well-covered elsewhere • Disadvantages • Can be edited by anyone • Information can be misleading, biased, or just plain wrong.
Wikipedia:Evaluating Articles • What’s the tone of the article? • Any tone other than a professional one increases the likelihood that the article is misleading or biased. • When was it last edited? • More recently edited articles are generally more frequently used and more likely to be correct. • Citations and references • More citations and references means the article is more likely to be accurate. • Like any source, there is no guarantee the information is 100% accurate.
Wikipedia:How should I use it? • You generally shouldn’t use Wikipedia as a sole source for your writing! • Initial and general information • Wikipedia is great for giving you general background on a subject. • References (at the bottom of the article) • Sources for getting more information. • Also help to verify the information in the Wikipedia article.
Google Scholar • Where do I find Google Scholar? • http://scholar.google.com • What sources is it looking at? • Includes peer-reviewed papers, theses, books, abstracts, and other scholarly literature from academic publishers and professional societies, and also from scholarly articles available on the Internet. • If you’re doing technical research or writing papers for your major, Google Scholar is a good place to look for existing work.
Google Scholar:how should I use it? • What do I use it for? • Good for finding papers, abstracts, and citations • A great way to search for diverse sources from one place • Provides full-text sources on the web, as well as locates the complete paper in your library • What advantages does it offer? • For each piece that it locates, Google scholar shows the title, other papers that have cited the article, related articles, and library links for electronic and physical papers • Allows you to search by title, author, and category, as well as within specific publications
Alternate Help Optionsfor CS101 • Google is only one option for finding what you need. • Microsoft Office’s website (office.microsoft.com) includes many useful tools for helping you to use the package’s features. • Check your book, and use any other resources you might have available (not including the person sitting next to you).
Library Databases • Visit the WVU Libraries website at http://www.libraries.wvu.edu/ • Retrieve peer-reviewed articles in full text • Use the information you find here to look for other sources and articles • Use the full-text databases, such as LexisNexis • These are good for contemporary, straightforward information • Other databases are available at http://www.libraries.wvu.edu/databases/
Some things to consider • When researching topics on the web, some things to think about are: • Who is the page’s author? Is the source credible? Sites like www.cnn.com will have more accurate information than sites like www.theonion.com. • How current is the information? Sites that have not been updated since 1998 are less likely to have accurate information. • Search engines are unfiltered and thus return all results. These may include results that aren’t objective or even accurate. Think about the possible biases that could be portrayed and whether the information and data is authentic. • You can double-check your information against multiple sources if you are unsure of their authenticity.