questions","basePath":"/gcse/computer-science/aqa/data-compression/questions","formulaUrl":null,"initialIndex":40,"initialQuestionWindow":[{"id":"ad569b4c-758c-4976-ba61-30b02b3237a5","revisionId":"62216e29-210c-4c1b-9e4f-d74b1741b06e","questionNumber":null,"questionType":"LA","specification":"Figure 1 contains a Huffman tree used to encode text characters.\n\n![Figure 1: A Huffman tree representing characters H, E, A, R, and T.](https://assets.mathsgenie.co.uk/aqa-qb/e6798a22-c2f5-407b-901c-47084b0c98d4.png)\n\nFigure 1 was used to encode a string, resulting in the following bit pattern:\n\n`011011011100`","difficulty":4,"difficultyBand":"easy","totalMarks":2,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"29674a3f-8b4a-440d-8db2-2c4e406a9e21","label":null,"content":"State the string that this bit pattern represents.","markscheme":"- Shows a correct method of traversing the Huffman tree to decode at least two characters (e.g., identifying that $01$ represents 'E' and $10$ represents 'A') M1\n- Correctly identifies the complete decoded string as \"EARTH\" A1","marks":2,"order":0,"markingRubric":null,"explanation":null,"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null},{"id":"ae1af48b-c4da-4400-b9a0-427601d82bd9","revisionId":"535ac39b-820f-4c27-b2b2-59c2b91dba16","questionNumber":null,"questionType":"LA","specification":"","difficulty":3,"difficultyBand":"easy","totalMarks":3,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"c2d25af2-4e00-41b8-a12b-e0bc6fa27cf6","label":null,"content":"Using the Huffman tree in the diagram, complete the table to show the Huffman coding for the characters **E**, **C**, and **SPACE**.\n\n![Huffman Tree](https://assets.mathsgenie.co.uk/aqa-qb/41e6dfd1-bf88-4afd-94e3-c1f8ab5d76f3.png)\n\n| Character | Huffman Coding |\n| :--- | :--- |\n| E | |\n| C | |\n| SPACE | |","markscheme":"- Identifies the Huffman code for **E** as $001$ A1\n- Identifies the Huffman code for **C** as $10$ A1\n- Identifies the Huffman code for **SPACE** as $110$ A1","marks":3,"order":0,"markingRubric":null,"explanation":null,"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null},{"id":"aebf05cf-e330-43a0-ac30-ac6ac8ed56e1","revisionId":"b771fd20-e3fb-4a57-98b7-e401399581c5","questionNumber":null,"questionType":"LA","specification":"An automated meteorological station records hourly wind directions. During stable weather conditions, this results in highly repetitive sequences of data (for example, multiple consecutive hours of 'East').","difficulty":3,"difficultyBand":"easy","totalMarks":2,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"84418a2a-bf4e-4b17-b67e-1902e7b54f54","label":null,"content":"Explain how Run-Length Encoding (RLE) compresses this wind direction data. You must include a specific example based on wind directions showing the sequence before and after compression.","markscheme":"- Explains that RLE detects consecutive repeated data values (runs) and represents them as a single data value paired with its frequency or count. M1\n- Provides a valid, clear example using wind directions showing the sequence before compression (e.g., 'East, East, East, North') and after compression (e.g., '3 East, 1 North' or '3E, 1N'). A1","marks":2,"order":0,"markingRubric":null,"explanation":null,"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null}],"subjectCode":"gcse_computer_science__aqa","summaries":[{"id":"01aceeda-575c-4ced-bc96-ba092de79c7e","difficultyBand":"medium","calculatorUse":null},{"id":"03fe5cea-6efd-45d9-aa60-75964ab4705a","difficultyBand":"easy","calculatorUse":null},{"id":"07d36a1a-5c14-476d-80ea-f2079e422bfb","difficultyBand":"easy","calculatorUse":null},{"id":"0ab264e5-e293-4736-91b6-fd500dfb6b02","difficultyBand":"easy","calculatorUse":null},{"id":"0fc37e4c-7cae-4c1a-9fb3-66f966107332","difficultyBand":"medium","calculatorUse":null},{"id":"1cb71686-bddf-4766-bac7-646e97cdb718","difficultyBand":"easy","calc

Data compression

Question 27

Data compression Questions

Data compression

Question 27

Data compression Questions