Presentation on theme: "Research methodology Rene Herrmann 2012. Exam guide (svenska) Examensarbetet kan utgöra en del av ett större forsknings- och utvecklingsarbete eller."— Presentation transcript:
Exam guide (svenska) Examensarbetet kan utgöra en del av ett större forsknings- och utvecklingsarbete eller projekt. Den enskilda studentens självständiga arbetsinsats skall dock alltid finnas dokumenterad. Den skriftliga dokumentationen bör omfatta åtminstone problemets relevans, anknytning till tidigare kunskap, frågeställning eller hypotes, metod, resultat och diskussion.
Exam guide (english) While the Bachelor´s thesis may constitute a part of a larger research work or programm, the individual student's independent contribution should always be documented. The written documentation should include at least an indication of the relevance of the problem, its relationship to existing knowledge, issue or hypothesis, methodology, results and discussion.
How to plan research The research produces knowlegde and the findings are reported to increase the body of knowlegde. The knowlegde to be produced follows the schematic described as research methodology. With respect to the students thesis a clear strategy is needed.
Strategy Relelance of the problem means the problem has to objectively exist. You are not the first one to discover that it does exist, therefore others have studied it before and in order to avoid academic overlap you study existing research related to your topic. The study produces information about the starting point, methods and results of competing research, doing exactly the same approach can not possibly produce new knowledge and is therefore useless.
Strategy(cont.) If you don’t know that you like to get to London you will never find the way, therefore does the research start with a clear hypothesis, question or issue. It is really relevant to understand that limits have to be drawn at that stage because a question (or alternatives) have bonderies, issues that are excluded, assumed small or noncontributing in that particular case.
Strategy (cont.) The goal of the thesis is the answer to the hypothesis, question. That means the result. If the research is to produce any result and study has to be done using a method. The method to be selected has to have the characteristic of being suitable but also different from the ones used in/by other research. This means that a question is studied using a different method than before and this in turn may result in new knowlegde.
Stragety - method selection This primary goal of this presentation is to help the student understand the importance of method selection and the consequences that arise from that selection. The method has to be suitable to the problem alternatively it is a method that was used by others for a similar problem but not exactly the same.
Method selection The method studies the problem systematically and it is therefore a theory. A theory is based on a model and the model has limitations of validity. At the limits of any theory or model the answers become more and more inaccurate. The researcher must decided if or if not a method is suitable and this means if the limiting factors of the method are within acceptable limits.
Methods and their limits A method (very often mathematical) assumes input data and uses this data to produce results (output) using an algorithm (function). Input is expected within certain ranges, output is provided with certain accuraccy. The function that handles data has limits (e.g. speed)
Exempel 1 Hypthesis: In Helsinki there is a correlation between the number of people that wear white hats and the number of people that are drunk. Method: On all days of the year you go to the city center and count, also on vappu. You compare the relative number of people with white hats to the relative number of people that are drunk. Result: You find especially for vappu that this hypothesis is very valid, basically all that have white hats are drunk, BUT on new years and around christmas you also find relative many drunks BUT they dont have white hats. Conclusion: Method was good because it revealed an answer to the hypothesis but the hypothesis was ill formulated because it was found wrong.
Example 2: Hypothesis/question: All marsians are green. Method: We use an infinite large net and filter the entire mars Result: We have all marsians and report that they are all whatever. Conclusion: The thesis is failed because you have no way of relaying on previous research showing that extraterrestial exist at all.
Example 3: Hypothesis: You study the seemily random fluctations of stock prices of large firms in normally stable economic enviroment and suggest price drop on Friday because people need cash and rise on Monday because people reinvest. Method: You use Fourier transform Result: You show there is a 5 day period in price developments Conclusion: Method is good but insufficient because it doesn’t shown if the price is high on Friday and low on Monday, just that it varies with 5 days
Example 4: Hypothesis: Earth gravitation is 9,81m/s^2 Method: Use a pendlum of length l and a clock to measure periodicity to calculate g. Result: You show it is somewhere there around 9,81m/s^2 but no error limits. Conclusion: Method good and fine but the hypothesis had no limits and the method used a clock of unspecified accurracy, therefore will the method produce output of unknown accuraccy. Method is insufficiently specified.
Regression and error in applying data to a model Regression is the fitting of data to a mathematical model by selecting optimal parameters for the model function. Selecting the wrong model function results in an bad fitting. The level of prefectness in modelling data to a mathematical function is expressed by the R^2 value. Regression of many different functions is possible in for exempel excel. If a function doesn’t exist, we may linearize our data and apply it to a linear function.
Statistical models and error If the study concerns statistical processes that follow gaussian behaviour we may correlate the measured data to an argument and based upon the number of measurements (tests) determine the statistical accurracy (error margin). This is popular on election day – estimating the outcome of the election based upon a set of data (not all votes counted yet)
Time series and frequency The inverse of time is frequency, the relation between these 2 is the Fouriertransform of these signals. If the data is numeric instead of analytic, the transform is numeric too, called FT or FFT. The fast you sample the higher the maximum frequency you can resolve, the longer you measure the larger the resolution. Exemple1: The moon circles earth in 28 days but you may also say the its frequency is 1/28 days. (trivial) Exemple 2: There are 52 fridays each year on which stocks fall 1friday/1week and there is a summer hole in trading also with low stock prices. The are 2 (and more frequencies), f2=1summer_hole/52weeks. The latest illustrates that signals with multiple frequencies are easier summerized using frequency rather than time.
That’s all folks, Thank you for your attention, a well planned thesis writes itself, one with an unsuitable method never gets ready!