Compare the following paraphrases with the original text, and check why the examples might be considered to be plagiarism.

*"As higher and higher speeds are used in wireless applications, error correction continues to pose a major design challenge. Recently, a new class of codes, called turbo codes, has emerged as a popular choice for third-generation wireless systems. Turbo codes exhibit performance, in terms of bit error probability, that is very close to the Shannon limit and can be efficiently implemented or high-speed use. A number of different turbo encoders and decoders have been introduced, most of which are based on convolutional encoding."* Stallings, W. (2005) Wireless Communications & Networks 2nd ed. New Jersey. Prentice Hall 2005 p220.

**Paraphrase 1**: *A new class of codes, called turbo codes, has become a popular choice for 3G wireless systems. The performance of turbo codes is very near to the Shannon limit and can be implemented efficiently for high-speed use*.

- paraphrase 1 has no reference to the original author
- although some words have been changed, the text is still in the author's voice not the student's voice.

**Paraphrase 2**: *A new class of codes, called turbo codes, has become a popular choice for 3G wireless systems. The performance of turbo codes is very near to the Shannon limit and can be implemented efficiently for high-speed use (Stallings, 2005, p220). *

- although the student has referenced the author here, the text is too close to the original. If there is no suitable way to paraphrase this information, a full quotation should have been used.
- it is not clear that the first sentence of the student's work is also based upon the author's text.

**Paraphrase 3:** *Stallings (2005, p220) states that turbo codes have become a popular solution to the problem of error correction for high speed wireless applications.This is due to their ability to operate close to the Shannon limit for transfer rate over a noisy channel. *

- although paraphrase 3 is written in the student's own voice, and they have made an effort to reference this correctly, it is not clear that the second sentence is also partly based on the original text.

**Paraphrase 4:**** ***Stallings (2005, p220) states that turbo codes have become a popular solution to the problem of error correction for high speed wireless applications due to their ability to operate close to the Shannon limit for transfer rate over a noisy channel.*

- paraphrase 4 shows one way the original text can be correctly paraphrased. By writing this in their own words and choosing what information to include, what to leave out and what to add, the student has demonstrated that they understand the text.
- this is clearly written in the student's voice rather than the author's
- the student has credited the author as the source of the information
- it is clear that all of the information has come from the author's original text.

(Adapted from http://libguides.calpoly.edu)