(1) Changing Knowledge

In the early part of the 20th century, astronomers engaged in a prolonged debate over what were then known as spiral nebulae—diffuse pinwheels of light that powerful telescopes revealed to be common in

the night sky. Some astronomers thought that these nebulae were spiral galaxies like the Milky Way at such great distances from the Earth that individual stars could not be distinguished. Others believed that they were clouds of gas within our own galaxy.

One astronomer who thought that spiral nebulae were within the Milky Way, Adriaan van Maanen of the Mount Wilson Observatory, sought to resolve the issue by comparing photographs of the nebulae taken several years apart. After making a series of painstaking measurements, van Maanen announced that he had found roughly consistent unwinding motions in the nebulae. The detection of such motions indicated that the spirals had to be within the Milky Way, since motions would be impossible to detect in distant objects.

Van Maanen’s reputation caused many astronomers to accept a galactic location for the nebulae. A few years later, however, van Maanen’s colleague Edwin hubble, using a new 100-inch telescope at Mount Wilson, conclusively demonstrated that the nebulae were in fact distant galaxies; van Maanen’s observations had to be wrong.

Studies of van Maanen’s procedures have not revealed any intentional misrepresentation or sources of systematic error. Rather, he was working at the limits of observational accuracy, and his expectations influenced his measurements. Even cautious researchers sometimes admit, “If I hadn’t believed it, I never would have seen it.”

(2) Discovering an Error

Two young faculty members—Marie, an epidemiologist in the medical school, and Yuan, a statistician in the mathematics department—have published two well-received papers about the spread of infections in populations.

As Yuan is working on the simulation he has created to model infections, he realizes that a coding error has led to incorrect results that were published in the two papers. He sees, with great relief, that correcting the error does not change the average time it takes for an infection to spread. But the correct model exhibits greater uncertainty in its results, making predictions about the spread of an infection less definite.

When he discusses the problem with Marie, she argues against sending corrections to the journals where the two earlier articles were published. “Both papers will be seen as suspect if we do that, and the changes don’t affect the main conclusions in the papers anyway,” she says. Their next paper will contain results based on the corrected model, and Yuan can post the corrected model on his Web page.

1. What obligations do the authors owe their professional colleagues to correct the published record?

2. How should their decisions be affected by how the model is being used by others?

3. What other options exist beyond publishing a formal correction?

Part 2 Comparison and Contrast

When you are speaking at university, you need to do much more than just give information. You should always be trying to do something with your speaking. One common function is comparing and contrasting, speaking about similarities and differences. There are many ways of expressing comparison and contrast in English.

Task 8. Look at the following table and read the text below. Pay attention to the comparisons and contrasts.

	Price	Processor Speed	Screen Size	Hard Disk	RAM
Evesham Axis 1.33 SK	�1,174	1.33 GHz	17"	40 GB	256 MB
Armani R850 P4.	�2,467	1.7 GHz	19"	40 GB	256 MB
Mesh Elite 1.7GT Pro	�1,938	1.7 GHz	19"	57 GB	256 MB
Elonex WebRider Pro	�1,174	1.2 GHz	17"	38.1 GB	128 MB

Compare your answer with the model:

We compared three personal computers, the Evesham Axis 1.33 SK, the Armani R850 P4 and the Mesh Elite 1.7 GT Pro, with respect to the following factors: price, processor speed and size of hard disk. The Evesham Axis, which costs �1,174, is by far the cheapest of the three, the Armani and the Mesh Elite costing �2,467 and �1,938 respectively. The Evesham Axis has the same hard disk size as the Armani, 40 MB, whereas the Mesh Elite is the largest at 57 GB. Regarding the processor speed, the Armani and the Mesh Elite are similar - the processor speed, at 1.7 GHz, being 0.37 GHz faster than the Evesham Axis.

Task 9. Using the above paragraph as a model, compare the Armani, the Mesh Elite and the Elonex with respect to price, screen size and amount of RAM.

	Price	Processor Speed	Screen Size	Hard Disk	RAM
Evesham Axis 1.33 SK	£1,174	1.33 GHz	17"	40 GB	256 MB
Armani R850 P4.	£2,467	1.7 GHz	19"	40 GB	256 MB
Mesh Elite 1.7GT Pro	£1,938	1.7 GHz	19"	57 GB	256 MB
Elonex WebRider Pro	£1,174	1.2 GHz	17"	38.1 GB	128 MB

LANGUAGE
COMPARISON	CONTRAST
The Evesham Axis is like the Elonex WebRider The Evesham Axis and the Elonex WebRider are similar The Evesham Axis is similar to the Elonex WebRider The Evesham Axis is the same as the Elonex WebRider The Evesham Axis resembles the Elonex WebRider	The Evesham Axis differs from the Armani The Evesham Axis is unlike the Armani The Evesham Axis and the Armani differ The Evesham Axis is different from the Armani The Evesham Axis contrasts with the Armani

Task 10. Using the example in the table and the phrases below make up your own examples with comparison and contrast.

with respect to price.

as regards price.

as far as price concerned.

regarding price.

in terms of price.

in price.

Task 11. Read the following examples and say what they mean comparison or contrast

The Mesh Elite has a large screen.

Similarly, it has a high capacity hard disk. Likewise, it has a high capacity hard disk. Correspondingly, it has a high capacity hard disk. It has a high capacity hard disk, too. It also has a high capacity hard disk.

Both the Evesham Axis and the Elonex WebRider cost �1,174. The Evesham Axis is as expensive as the Elonex WebRider. The Evesham Axis costs the same as the Elonex WebRider. The Evesham Axis is the same price as the Elonex WebRider.

Task 12. Students at university need to organise their lives, control their finances, keep records of phone numbers, remember assignment and exam dates etc. Some students use paper diaries and notes for this, but the use of electronic Personal Data Assistants is becoming more popular. The table below compares 19 PDAs.

Using the information given in the table, recommend one of the PDAs for general student use. You will need to describe what a student has to do, describe some of the PDAs, compare and contrast the ones you have chosen, look at advantages and disadvantages and finally recommend one.

PDA	Price	Operating System	Memory	Size	Weight	Power	Screen Size
Casio Cassiopeia E-125	£499	Microsoft Pocket PC	32MB	131 x 84 x 20mm	250g	Rechargeable Lithium-Ion	240 x 320 pixels
Casio Cassiopeia EM-500	£399	Microsoft Pocket PC	16MB	128 x 82 x 19mm	218g	Rechargeable Lithium-Ion	240 x 320 pixels
Compaq iPaq H3630	£449	Microsoft Pocket PC	32MB	130 x 83 x 16mm	179g	Rechargeable Lith-Polymer	240 x 320 pixels
Compaq iPaq H3130	£338	Microsoft Pocket PC	16MB	130 x 83 x 16mm	163g	Rechargeable Lith-Polymer	240 x 320 pixels
HandEra 330	£335	Palm OS	8MB	81 x 121 x 17mm	167g	4 x AA batteries	240 x 320 pixels
Handspring Visor Deluxe	£144	Palm OS	8MB	130 x 83 x 16mm	163g	2 x AAA batteries	240 x 320 pixels
Hanspring Visor Edge	£269	Palm OS	8MB	119 x 79 x 11mm	136g	Rechargeable Lithium-Ion	160 x 160 pixels
Handspring Visor Prism	£349	Palm OS	8MB	120 x 75 x 21mm	194g	Rechargeable Lithium-Ion	160 x 160 pixels
Handspring Visor Platinum	£189	Palm OS	8MB	122 x 76 x 18mm	153g	2 x AAA batteries	160 x 160 pixels
HP Jornada 548	£389	Microsoft Pocket PC	32MB	118 x 79 x 18mm	260g	Rechargeable Lithium-Ion	240 x 360 pixel
HP Jornada 710	£599	Windows for Handheld PC 2000	32MB	189 x 95 x 34mm	510g	Rechargeable Lithium-Ion	640 x 260 pixels
HP Jornada 720	£665	Windows for Handheld PC 2000	32MB	189 x 95 x 34mm	510g	Rechargeable Lithium-Ion	640 x 260 pixels
Palm m05	£169	Palm OS	8MB	79 x 118 x 18mm	125g	2 x AAA batteries	160 x 160 pixels
Palm m500	£329	Palm OS	8MB	114 x 79 x 10mm	113g	Rechargeable Lithium-Ion	160 x 160 pixels
Palm m505	£399	Palm OS	8MB	114 x 79 x 10mm	139g	Rechargeable Lithium-Ion	240 x 320 pixels
Psion Revo Plus	£300	EPOC 5	16MB	79 x 157 x 17mm	200g	Rechargeable N1MH	480 x 160 pixels
Psion 5MX	£400	EPOC 5	16MB	90 x 170 x 23mm	320g	2 x AA batteries	640 x 240 pixels
Sharp ZQ-770PC	£100	Proprietary	3MB	82 x 160 x 20mm	220g	2 x AA batteries	239 x 80 pixels
Sony Clié (PEG-S300)	£199	Microsoft Pocket PC	8MB	71 x 115 x 15mm	121g	Rechargeable Lithium-Ion	160 x 160 pixels

Task 13. Compare and contrast two closely related terms used in your field in order to show their similarities and differences:

Example Term a: computer Term b: word processor

A computer is a device that is similar to a word processor in that it can be used to produce and edit text; however, it differs from a word processor in that it can be programmed and can be used for other applications, such as spreadsheets and databases.

Term a: Term b:

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Task 14. (out-class) Read the article (text B) and find the examples of comparison and contrast. (The text is in CD)