Hedging in Data Commentaries

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You are a teaching assistant for an introductory biology course with a total enrollment of 150. Exams are usually given in the evening to avoid losing valuable class time. Because some students have evening commitments, a makeup exam is always given. The professor has noticed a big discrepancy between the scores of the last regular exam and those of the makeup exam. Because you administered the last makeup exam, you have been asked to offer an explanation. You have prepared the data in Table 16. Now write a data commentary, either as a formal report or an e-mail message to your professor.

Table 16: A Comparison of the Regular and Makeup Exam

Items	Regular exam	Makeup exam
Average score (out of 100) Time administered Difficulty of questions Number of students Proctor Board examples Room environment	86 Wednesday, 7:00 p.m. average 125 professor yes about 20C	72 Friday, 4:00 p.m. average 25 teaching assistant no (not considered necessary) about 28C

Dear Professor,

I hope this email finds you well. I am writing this email to present the result of my analysis on the discrepancy observed in the two tests based on the above table.

It is clear that there is a big gap between the average scores of the regular exam and the makeup exam. The first thing that I would like to mention is the possibility of the fact that, some of the students who attended the make-up exam were not well-prepared for the regular exam and chances are that they could not get fully prepared in the last two days.

Since you were the proctor of the regular exam, the student have benefited from your help, hints and of course the board examples during the exams, whereas I did not answer to any questions based on regulations.

In the regular exam there were 125 students attending the test whereas in the makeup exam only 25 students were taking the test. I don’t want to accuse anyone of misbehavior during the exam; however, since you were the only proctor of the exam, the high number of students could increase the chance of cheating in the regular exam.

Finally, since the room's temperature was considerably higher in the makeup exam, that might also be a good reason for the less efficient performance of the students.

I hope these reasons would be convincing and justify the discrepancy between the two exams.

Should you have any more questions, please don’t hesitate to contact me.

Best regards,

TA

Discription of Graphs

Time-response of a second-order system

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This graph illustrates the time-response of a second-order system to a unit step input. There is several information in this graph which describes the behaviors and characteristics of the system. The rise time tr, is the time it takes for the response of the system to go from 10% to 90% of its final value. The settling time indicates the time it takes for the response to settle within 2-5% of its steady-state value. The smaller this value is, the faster response the system has to unit step input. Overshoot b, is the height of the first peak. The smaller the overshoot is, the smoother the system behaves. The damping factor of the system fd ,is related to the overshoot ratio and the time it takes for the overshoot to appear in the response (tp). The main characteristics of any system which could be represented by a second-order transfer function, can be explained through this response. This is a general graph which explaines a family of second-order systems. That is why it is described in terms of parameters rather than specific values or numbers.

Northbound Gray Whales Statistics by Week

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Click on the image to enlarge

The above graph is the Northbound gray whales counted by week in spring migration 2010 in Los Angles, California.
As can be seen, the graph approximates a normal distribution of whales migrations during the months of February to May.  As shown in the graph, we have the least counts of whales close to the margins of the count period, i.e. the first week of February and the last week of May. It can be clearly seen that the number of whales migrated, has an increasing trend till the third week of March. The graph has its peak at the third week of March. There is a dip of 60 between the first and third week of March which is an exception to this upward movement. Then passing the peak of the graph in the third week of March, the number of whales migrated will start declining until the end of the report period. There is again an exception between April 12 and April 18 to this trend. 
This increasing and then decreasing trends could be explained by the fact that, as we approach the mid March, the environmental changes in this region are more ideal for the migration of gray whales. So most of the gray whales migrate in this period.

A Condensed Method Section on an Interview by Mei-Lan

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The research has been carried out to determine, whether the prevailing myths: Chinese communities would always look after their elderly, were in fact true. This is an interview- type research. The data were collected from subjects, who were chosen from local Chinese communities, in big cities in the east and west coasts. The subjects were introduced by friends, and friends of friends of the interviewer.

Due to the lack of time and some other constraints, only about ten people were interviewed, which was not enough data for any type of statistical analysis.

A face-to-face interview technique was used, to increase the integrity of the research. Each interview lasted around an hour. A so called "semi-structured" interview was used, that is, not the same amount of questions were asked from all interviewees.

The interviewees were free to speak with any of Mandarin, Taiwanese, or English languages. This is a strong point of this research method, because the interviewees could express themselves more freely.
Overall, an appropriate technique was used in  this interview, however, the low number of interviewees decreased the liability of the research. 

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Book Summary

Who Moved My Cheese?

A best-seller book by Spencer Johnson.

Here is a link to the book in Google books.

In my humble opinion, this book is worth reading and can be bought as cheaply as 16.99 $ from Google books.
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"Who moved my cheese" is a great short story by Spencer Johnson, the co-writer of "1-Minute Manager," and several other books. The book is written in big print on 94 pages, which can be read in less than 2 or 3 hours.

"Who moved my cheese?," is a book about and around the concept of "CHANGE". "Cheese," is a metaphor for goals in life.  This manuscript is a brief parable for those who want to step back for some moments and analyze the effect of change in their life. Spencer Johnson nicely answered an important question, "What would you do if you weren't afraid of change?!". Fear is the main hindrance to change, he has pointed out this fact in the book.

The author used animal metaphors as well as humans to form the four characters of the story. Two mice named, Sniff and Scurry and two little men Hem and Haw, the same size of mice. The author used these characters to represent different approaches people choose to achieve their goals.

The four characters all live in a maze, each having a different journey looking for cheese. Sniff as the name indicates, is good at sniffing, always looking for new opportunities. Scurry is good on working on the newly discovered cheese. He rushes toward the opportunities which have been already found by others. On the other hand, Haw and Hem are of more analyzing minds. They treat changes and new opportunities more philosophically. Although Haw is more comfortable with sticking to the old habits, but still ready to put the past attitude away and accept changes when necessary. Hem however strongly resist to changes.

At first, all of the four characters are putting a good amount of efforts searching through the maze to find cheese. Eventually, they all find a room full of cheese. They used to go there day after day to eat cheese. However, one day, they came to the room and found no more cheese there. Their different approaches in dealing with this new situation forms the main theme of the story. Sniff and Scurry soon decided to go back, searching in the maze for new cheese, however, Haw and Hem started analyzing the situation and stayed in the room. They came every day to the empty room with the hope that the cheese would be back. They became hungrier and hungrier everyday. At some point Haw realized that waiting for the cheese to come back is of no benefit. So he decided to start his journey alone in the maze in pursuit of new cheese, when he couldn't convince Hem to accompany him in the journey.
Sniff and Scurry end up with a room full of different cheese. Haw eventually joined them with some delay, however Hem was still not there because of his tendency to reject changes.
The concluding points are:

• It is a fact: Change happens, so you need to evaluate it, adapt to it, accept it and then enjoy the change and be ready for change once again and again and again.

Review the Literature: Citation Theories Example

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Citations are widely recognized as being an important and distinctive property of academic texts. As a consequence, the presence or absence of citations allows the casual reader to get an immediate sense of whether a text is an “academic” or “popular” one. Because citation is such an obvious surface phenomenon, it has been much discussed in the academic world. Indeed, there are several theories about the role and purpose of citations in academic texts. 

There are many different theories why citation is needed. Some of these theories are listed below according to their importance from blogger's point of view: 

The most important of all, citations are used to recognize and acknowledge the intellectual property rights of authors. They are a matter of ethics and a defense against plagiarism. Citations are also used to create a research space for the citing author. By describing what has been done, citations point the way to what has not been done and so prepare a space for new research (Swales, 1990). It is also worth mentioning that citations are tools of persuasion; writers use citations to give their statements greater authority (Gilbert, 1977). From a different aspect, citations are used to show respect to previous scholars. They recognize the history of the field by acknowledging previous achievements. A less common theory is that citations are used to supply evidence that the author qualifies as a member of the chosen scholarly community; citations are used to demonstrate familiarity with the field (Bavelas, 1978). Another weak theory is that citations operate as a kind of mutual reward system. Rather than pay other authors money for their contributions, writers “pay” them in citations (Ravetz, 1971).

  

A summary of Jared Diamond's speech on why societies collapse

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You can find the complete speech here.

This is a summary of Jared Diamond TED speech on why and how societies collapse.

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Jared findings are focused on the mystery of societies which have collapsed, the reasons behind fragility of societies and the tips which can be used to avoid it.  

First, what is understood from his speech is that, there is no single factor which would cause society's collapse, but there s a set of different factors. Jared's findings summarizes these factors as a five- point checklist as follows:

1. Human impact on the environment in destroying the resources
2. Climate change
3. Relations with neighboring friendly societies.
4. Relations with hostile societies.
5. Political, economical, social and cultural factors in society that determines the society's capability to solve the environmental problems.

Based on his speech, the three main common themes behind different collapses are:
First, rapidity of collapse after a society reaches its peak. Second, environmental factors that make some societies more brittle than others. And the third theme is divided into two main factors: Conflicts between short-terms interests of decision-makers, and long-term interests of society, strongly held values which are misused in irreverent situations.

To help avoiding these problems, we should work towards understanding those things we don't know and to work towards putting in action, those things we have understood so far.

Summarized by M.Goli, February 11, 2013

IEEE Citation Reference [1]

Citation standards for IEEE publication varies slightly for different resources. Here are some examples for IEEE citation format:

• Book 

Basic format: 
[#] J. K. Author, “Title of chapter in the book,” in Title of His Published Book, xth ed. City of Publisher, Country if not USA: Abbrev. of Publisher, year, ch. x, sec. x, pp. xxx–xxx. 
- Examples
[1] B. Klaus and P. Horn, Robot Vision. Cambridge, MA: MIT Press, 1986. 
[2] E. F. Moore, “Gedanken-experiments on sequential machines,” in  Automata Studies (Ann. of Mathematical Studies, no. 1), C. E. Shannon and J. McCarthy, Eds. Princeton, NJ: Princeton Univ. Press, 1965, pp. 129-153.

• Handbook

Basic format: 

[#] Name of Manual/Handbook, x ed., Abbrev. Name of Co., City of Co., Abbrev. State, year, pp. xx-xx. 

- Example

[1] Transmission Systems for Communications, 3rd ed., Western Electric Co., Winston-Salem, NC, 1985, pp. 44–60.

• Conference Technical Articles

Basic Format: 
[#] J. K. Author, “Title of paper,” in Unabbreviated Name of Conf., City of Conf., Abbrev. State (if given), year, pp.xxx-xxx. 

   1. Periodicals

"NOTE: When referencing IEEE Transactions, the issue number should be deleted and month carried. 
Basic Format", [1]: 
[#] J. K. Author, “Name of paper,” Abbrev. Title of Periodical, vol. x, no. x, pp. xxx-xxx, Abbrev. Month, year. 
- Example: 
[1] R. E. Kalman, “New results in linear filtering and prediction theory,” J. Basic Eng., ser. D, vol. 83, pp. 95-108, Mar. 1961.

   2. Theses (M.S.) and Dissertations (Ph.D.) 

Basic Format: 
[#] J. K. Author, “Title of thesis,” M.S. thesis, Abbrev. Dept., Abbrev. Univ., City of Univ., Abbrev. State, year. 
[#] J. K. Author, “Title of dissertation,” Ph.D. dissertation, Abbrev. Dept., Abbrev. Univ., City of Univ., Abbrev. State, year. 
- Example: 
[1] J. O. Williams, “Narrow-band analyzer,” Ph.D. dissertation, Dept. Elect. Eng., Harvard Univ., Cambridge, MA, 1993.

Reference:

[1] D. Graffox. (2009, Sept.). IEEE Citation Reference [Online]. Available: http://www.ieee.org/documents/ieeecitationref.pdf

A talk with the Librarian,

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1. If a student is looking for a book which he/she can not find it in any of the libraries of GWU, how should he/she proceeds to submit a request for the book. What is the GWU policy in this regard and how will the GWU library accommodate the student in such circumstances?

2. What are some other services, the GWU library offers to students, which might be beneficial particularly to graduate students? (Tutorials, workshops, book grants and loans, part-time job positions, etc...)

3. How can we interact with other libraries in the world through our membership in GWU library?

Language and Gender: A brief literature review

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In this post, we aim to answer several questions regarding a brief literature review on Language and Gender (Click here to go to the article).

     1. What are the general sequence of points covered in the review? 

  The author(s) has tried to point-out and shortly analyze the two opposing approaches dealing with the topic of Language and Gender, namely gender power perspective and gender-based subcultural behaviors perspective. 

     2. Why does the writer adopt this sequence? 

  The author has adopted this sequence to conclude that, the two major approaches proposed so far are not mutually exclusive, but a third approach which would fairly consider both approaches, would probably describe the problem in a more comprehensive manner.

     

     3. Does the writer simply list previous studies or does she/he provide an evaluation of these studies? List some specific examples. Both. In some of the studies the author evaluate the main idea of the article and in some others she/he simply list the ideas. 

Some examples of the former are: 

•   Lakoff's (1975)- While there are clearly some problems with Lakoff's work - her analysis was not based on empirical research, for example, and the automatic equation of subordinate with `weak' is problematic - the emphasis on dominance has understandably remained at the Centre of much of this work.

 Where some examples of the latter are:

• Zimmerman and West, 1975). The chief focus of this approach, then, has been to show
  how patterns of interaction between men and women reflect the dominant position of men in
  society.

• Maltz and Borker (1982)- Much of this research has focused on comparisons between, for example, the competitive conversational style of men and the cooperative conversational style of women.

      4. Does the writer's review sound reasonable and balanced?

  Although the author has briefly argued the different approaches in Language and Gender and not thoroughly investigated the previous studies, however his/her overall conclusions seems balanced since he/she unfavorably considered both major views in the field.