## Definition Give a detailed, accurate account of a situation, event, pattern, or process—stating _what_ happens, _what_ something is, or _how_ a process works *Verb. Noun form: description.* ## Characteristics - Answers *what* something is or *how* a process works; - builds on a connected series of [[state|statements]]; - draws on facts or known features; - does not require discussion of cause; and - can include examples. ## Examples ### Describe cats - Cats are small furry mammals; - they usually have four legs and a tail; and - they can be very affectionate or extremely hostile—there is not much of an in-between. ### Describe longshore drift - Waves approach the beach at an angle, determined by the prevailing wind; - swash carries sediment up the beach at this same angle; - backwash then carries sediment back down the beach at right angles, pulled by gravity. ### Describe the format of an IPv4 address - Is 32 bits long; - usually represented in denary: - written as four separate groups of eight bits (called octets); - each denary number is separated by `.`s; and - each denary number must be between 0 and 255 inclusive. - e.g., 192.168.0.1 ### Describe the fetch-execute cycle - The address of the next instruction is held in the program counter; - the control unit fetches the instruction at this address from memory; - the instruction is placed in the memory data register; - the program counter is incremented; - the control unit decodes the instruction, splitting it into an opcode and any operands; - the control unit executes the instruction, using the ALU where arithmetic or logic is required; - the cycle then repeats. ### Describe the binary search algorithm - The middle item of the list is checked against the target value; - if the middle item matches the target, the search ends; - if the target is smaller than the middle item, the right half of the list—including the middle item—is discarded; - if the target is larger than the middle item, the left half of the list—including the middle item—is discarded; - this process repeats on the remaining part of the list, checking its middle item each time; - the search ends when the target is found or there are no items left to check. ### Describe the features that make a payroll processing system solvable by computational methods The following response builds on [[identify#Identify the features of a payroll processing system that make it solvable by computational methods|this identification]]. Payroll processing involves a vast amount of data that needs to be processed, including thousands of employee records and tax information that varies by region. The task is repetitive—the same set of calculations is applied to each employee in turn, with variability introduced by factors like regional tax rules. The inputs and outputs are also clearly defined, with a fixed set of fields expected for each record and a consistent output format required for every payslip. The above response could be improved with [[justify#Justify the features of a payroll processing system that make it solvable by computational methods|justification]] and [[explain#Explain why a payroll processing system is amenable to a computational approach|explanation]]. ## Non-examples - [[state|Statement]]—a single brief fact, rather than a connected series of facts. - [[identify|Identification]]—picks out an answer from a set of possibilities, without elaboration. - [[explain|Explanation]]—considers *why*, rather than just *what* or *how*.