Tradeoffs Associated with digital data 1-10

9) A freshman in a college statistics class created and conducted a survey asking other students about their personal hygiene routines. She created a shared spreadsheet and decided to give every student at the university full access to this spreadsheet so that they could enter their answers to the survey questions themselves. After the survey was over, she published the results by changing the spreadsheet's access to "view only". The following survey questions were asked and this information was entered by the individual students into the shared spreadsheet: What is your hair color? How many times do you shower each week? How often do you wash your hair each week? Do you use deodorant? What dormitory do you live in? Which floor of the dormitory do you live on? What is your gender? Which state do you live in when not in college? Of the following, which is the LEAST likely to be an issue with this approach? A A participant changes his/her published hygiene information to match the hygiene habits of other students. B Hygiene routines of an individual student could be identified by the information entered into the spreadsheet. C Bogus information is entered into the spreadsheet to indicate poor hygiene for other fellow students. D Students are reluctant to enter their true information because they fear that other students will discover their identities and make fun of them.

Choice 'A' is the correct answer. The stated survey approach mentions that once the survey is published, the shared spreadsheet is given "view only" status, which means that students can only view the results. Therefore, students would not be able to change their individual information after the survey is published. Explanation of Distractors: Choice 'B' is an incorrect answer. It is definitely possible that hygiene habits of an individual student could be identified by the information entered into the spreadsheet. By using a combination of dormitory, floor, gender, state of residence, and hair color, you could narrow down the list of possible students significantly and possibly to only one individual. Choice 'C' is an incorrect answer. College students are known for pranks and it is very likely that fake data is entered into the spreadsheet either as a prank or maliciously to make fun of a fellow student. The actual name of the student could purposely be entered as the answer to one of these questions to pinpoint a student. Choice 'D' is an incorrect answer. Since students know that this information can be viewed by other people, they may be very reluctant to enter true answers. The student may enter wrong identifying information or may enter incorrect answers for the hygiene questions if they view their hygiene routine as abnormal.

7) When storing data digitally, whether through cloud computing or locally, there is an increased risk of theft due to the relative ease of accessing the information. Which of the following is NOT an example of security and privacy concerns that arise from storing data digitally? A A manager looks up an employee's birthday in the online company directory in order to plan a surprise birthday party for them at the office. B A company pays for a Distributed Denial of Service (DDoS) attack that shuts down a competitors website for an extended period of time. C An insurance company has a breach in their server that was accessed through stolen user credentials and more than 80 million records were compromised. D A celebrity's phone is remotely accessed and photos are downloaded and sold to a magazine company.

Choice 'A' is the correct answer. While the manager is accessing personal information, that information is not being given to anyone outside of the office. Also, the manager is granted access to this information and retrieved it legally. Explanation of Distractors: Choice 'B' is incorrect. While a DDoS attack does not retrieve any information, it shuts the website down and effectively closes the business for several hours. By overwhelming the server that the website is stored on, they take advantage of the data being stored virtually and choke the pathway to that data. Imagine if this happened to a hospital or a school. At a hospital, without access to digital files, doctors and nurses would not have access to vital information such as allergies and blood type. In a high school, without access to digital student records, parents may not be able to check out their children. Choice 'C' is incorrect because sensitive personal information was retrieved from the server by a fake employee. Choice 'D' is incorrect. Many phones now store photos using cloud computing to save memory on the phone. Because the photos are stored on the cloud, it can be retrieved without the owner's permission.

6) There is growing preference in today's age for streaming music over purchasing music. For what reasons might people prefer streaming over purchasing music? Select TWO answers. A Streaming music allows for the best listening experience due to lossy compression. B Streaming music is cheaper as most streaming services are free or charge low subscription fees. C Purchased music that is compressed using lossless compression is of higher quality as compared to streamed music. D Purchasing and downloading music takes up storage space on the device

Choice 'B' and Choice 'D' are correct. Choice 'B' represents one of the positive aspects of streaming music-that there is no or low cost to listen to music. The low-cost subscriptions range from approximately $10-15 and give the user access to nearly unlimited music options. For the same cost, the user can purchase a single album and listen to a limited number of songs. Choice 'D' represents one of the drawbacks of purchasing and downloading music. The number of songs that the user can listen to is limited by the storage capacity of the device, whether it be a phone, a computer, or other device. Streaming, on the other hand, doesn't require storage space for the music. Explanation of Distractors Choice 'A' is incorrect. Lossless compression, not lossy compression, would allow for the best listening experience. Since data is lost under lossy compression, the sound quality would be lower (for lossy compression). Choice 'C' is incorrect. This is true but it does not represent a reason why people prefer streaming over purchasing music. Rather, the fact that purchased music that is compressed using lossless compression is of higher quality supports the case for purchasing music rather than streaming it.

8) Data compression is the process of transforming a file so that it uses less bits than the original file, thereby reducing its file size. Which of the following is NOT true concerning data compression? A If the same file is compressed using lossless compression and also compressed using lossy compression, the lossless-compressed file would generally have a larger file size than the lossy-compressed file. B A compressed file cannot be restored to its original format unless the person trying to restore the file has decryption rights. C If a video file is compressed 1,000 times, alternating each time between using lossy compression and lossless compression, the quality of the resulting video will likely degrade from the original file. D File size and loss of information are two considerations when deciding on which compression technique to use.

Choice 'B' is the correct answer, since it is false. Compression and decryption are two different processes. Compression is used to reduce the size of a file, so the file can be stored or transmitted using less bits. Compression typically does not use encryption to hide the content of the file. If a person has a compressed file that uses a lossless format and they know what format it is stored in, the person can easily restore the file to its original format. The person does not need a key or decryption rights in order to restore it. Explanation of Distractors Choice 'A' is an incorrect answer, since it is true. Lossy compression loses some of the information from the original file. The only reason to use lossy compression is to have a smaller file size than when lossless compression is used. Choice 'C' is an incorrect answer, since it is true. Lossless compression will not affect the quality. However, every other time that the file is compressed using the lossy compression technique, it loses part of its data and thereby loses some of its quality. This loss of data is not that noticeable at first, but gradually the quality of the video becomes noticeably inferior from the original video. Choice 'D' is an incorrect answer, since it is true. The two biggest trade-offs when considering the type of data compression to use are file size and loss of data. If the requirement is to not lose any of the data from the original file, then a lossless compression technique is the way to go. If a small file size is very important and you can live with a slight and possibly imperceptible loss of data, then lossy compression would be the preferred method.

3) Storing large amount of data comes with challenges. Which of the following statements are true regarding data storage? I. Storing personal information requires a secure network since cybercriminals will try to hack the account and steal the data. II. Careful planning is needed when determining the appropriate data storage for your data. III. Since data is stored as digital data instead of hard copies, there is less fear of it getting lost or stolen. A I only B I and II only C II and III only D I, II, and III only

Choice 'B' is the correct answer. Digital data representations involve trade-offs related to storage, security, and privacy concerns. Information stored digitally grants easier access to the rightful owners as well as cybercriminals. Cybercriminals hack to get personal information that they can sell. Therefore, storing large data sets that contain personal information pose a security risk. Depending on the size and usage requirements for the data set, you have to carefully plan where you store the data. Explanation of Distractors While most data is stored digitally instead of physically, the risk that the data could be lost or stolen is still there. In fact, because storing data digitally allows for greater access, there is a greater risk! Thus, Choices 'A', 'C'and 'D' are not correct.

1) In order to send large files more quickly and in fewer packets, they are compressed. Which of the following statements is TRUE about a compressed text file? A You only need to send the compressed document because text compression has a universal protocol. B You need to send the compressed text and the key. C You need to send the compressed text, the key, and the original text. The original text is not accessed but is there in case the reassembly of the compressed text cannot be achieved the computer can access the original file. D None of the above.

Choice 'B' is the correct answer. If you send the compressed text alone, the receiving computer will not know how to decode the message. Therefore the key must be sent with it. It is unnecessary to send the original file since the original file can be decoded using the key and the compressed text. Explanation of Distractors: Choice 'A' is incorrect because there is no universal protocol for encoding and decoding messages. Therefore a key must be sent with the compressed text. Choice 'C' is incorrect because with the compressed text and the key you can decode the message. The whole point of compressing files is to decrease the file size. Therefore sending the compressed text, the key, and the original text would be redundant. Choice 'D' is incorrect because you simply need the compressed text and the key to decode the message.

10) Tyrese is editing and applying a filter to his picture so that he can upload it to his social media page. Filters work by manipulating the RGB colors of the image and replacing the original image with the new image. Which of the following is considered lossless? Select TWO answers. A Cropping the picture to 3x3 but leaving the colors the same. B Averaging the RGB in each pixel to create a grayscale image. C Increasing the scale of all blue pixels by 50 to make the sky look richer. D Turning down the brightness of the image by decreasing all three colors by 75.

Choice 'C' and Choice 'D' are the correct answers. Choice 'C' is correct because you can retrieve the original image by simply decreasing the color of all blue pixels by 50. Choice 'D' is correct because you can retrieve the original image by simply increasing all color pixels by 75. Explanation of Distractors: Choice 'A' is incorrect because you cannot retrieve the cropped portion of the image and that data is lost. Choice 'B' is incorrect since you covered the red, green, and blue colors into one gray pixel, the original data is lost and the original file cannot be retrieved.

5) A researcher is conducting an experiment to determine the effects of different amounts of sunlight and water on the growth of tulips. The growth of the tulip can be categorized with a rating from 1-10 (1 = no growth, 10 = outstanding growth). There are 1,000 tulips to be analyzed and each is identified with a number from 1 to 1,000. There is no requirement about how the experimental data is collected. Once the data is collected, the information needs to be analyzed and published within one day to meet a publication deadline. Which is the BEST approach for collecting and storing this data, in preparation for generating a published report? A Store the sunlight and water data for each individual tulip into separate text files. Take an individual photo of each tulip to show the growth of the tulip. All of these files will include the tulip number in the name of the file. B Store the tulip number, sunlight amount, and water amount for each tulip in a single row in a spreadsheet. Take an individual photo of each tulip to show the growth of the tulip. Each image file will include the tulip number in the name of the file. C Store the tulip number, sunlight amount, water amount, and growth rating for each tulip in its own row in a spreadsheet. D Take an individual photo of each tulip to show the growth of the tulip. Store the tulip number, sunlight amount, water amount, and a link to the tulip image in a single row in a spreadsheet.

Choice 'C' is the correct answer. Since the researcher is publishing the results of a research experiment, he/she will most likely need to show quantitative data. This choice explains that the data for each individual tulip is stored in a separate row of a spreadsheet. Using a spreadsheet allows the data to be sorted, filtered and analyzed very quickly. Also, spreadsheet information can easily be converted into graphs, which can be inserted into a published report fairly quickly. There is no requirement that a picture of each tulip be taken, which is a time-consuming process. Explanation of Distractors Choice 'A' is an incorrect answer. Of the choices, this is probably the least preferred since it will result in many different files. One issue is that it will be difficult to organize and manage all of these files. Also, it does not mention a quantitative growth rating for each tulip. In order to get this rating, the researcher will likely need to view every tulip photo and make a decision on the growth before publishing the report. Compiling all of this data would be very time consuming and not preferable if a report needs to be published in a short time frame. Choice 'B' is an incorrect answer. This choice is partially good, since it mentions one row in a spreadsheet to store each tulip's water and sunlight data. However, in order to make a decision on the tulip's growth before publishing the report, the researcher would have to locate and view the image file for each tulip. Compiling all of this data would be very time consuming and not preferable if a report needs to be published in a short time frame. Choice D Choice 'D' is an incorrect answer. This choice is partially good, since it mentions one row in a spreadsheet to store each tulip's water and sunlight data. Another good point is that it does include a link to the tulip. However, in order to make a decision on the tulip's growth before publishing the report, the researcher would have to view the image file for each tulip. Compiling all of this data would be very time consuming and not preferable if a report needs to be published in a short time frame.

2) Data security is a very important concern for corporations in today's world. Which of the following, is considered to be the LEAST threatening to the security of corporate data? A Malware infections. B Database privileges that go beyond the requirements of the job. C Human negligence D Computer network disruptions

Choice 'D' is the correct answer. Although computer network disruptions can be very troublesome, they are not a cause for security concerns. Network disruptions typically make the corporation's computer systems inaccessible to everyone, not just their own employees. Explanation of Distractors: Choice 'A' is an incorrect answer. Malware infections are a continual problem. Once a computer is infected, malware can quickly spread to other computers in the corporation's network and potentially expose their data to an outside threat. Choice 'B' is an incorrect answer. When corporate employees are given privileges that exceed those needed to do their job, they are given the ability to see information that they should not have access to. There could be a temptation to abuse this privilege and provide sensitive information to outsiders in exchange for compensation. This is an important but sometimes overlooked threat to corporate data. Choice 'C' is an incorrect answer. Human negligence is one of the top factors in security breaches. For example, when employees use weak passwords or inadvertently communicate their login information to outsiders, the corporation's data could be exposed to outside threats.

4) One way of communicating hexadecimal color codes is in the following way: #RRGGBB. The first pair of numbers represents the red color value (R), the second pair represents the green color value (G), and the third pair represents the blue color value (B). Sometime a simplified color code scheme is used that follows this format: #RGB. In this format, only the first digits of each color component from the original format are used (#RRGGBB). Which of the following is true about using the simplified color scheme? A Using the simplified color code represents lossless compression because it captures the same color as the original color code. B Using the simplified color code represents lossless compression because only some of the data is lost. C Using the simplified color code represents lossy compression because it captures the same color as the original color code. D Using the simplified color code represents lossy compression because it only approximates the original color.

Choice 'D' is the correct answer. Using the simplified color code will result in a loss of data and a resultant loss in the quality of the color. The exact values for the red, green, and blue components of colors will be lost. When converting back to the original color code, the second digits of each color component can only be guessed. Lossy compression does reduce storage and transmission demands; additionally, the difference between colors from the original color code and colors from the (lossy) simplified color code is generally not noticeable. Explanation of Distractors Choice 'A' is incorrect. There is an elimination of data under the simplified color code so this process is lossy, not lossless. For this reason, lossy data compression cannot capture the exact same color as the original color code. Choice 'B' is incorrect. If this were a lossless process, then none of the data would have been lost. Eliminating the second digit of each color component does result in data loss. Choice 'C' is incorrect. There is an elimination of data under the simplified color code so this process is lossy. For this reason, lossy data compression cannot capture the exact same color as the original color code.