diff --git a/Feedback - Common mistakes from 2019.md b/Feedback - Common mistakes from 2019.md index d4b3c99..933aabf 100644 --- a/Feedback - Common mistakes from 2019.md +++ b/Feedback - Common mistakes from 2019.md @@ -1,24 +1,3 @@ -# Background - -- Only giving the "popular science" definition of TSP. You need to be more precise/technical, using appropriate notation. -- Defining multiple versions of TSP and not being clear on which version you are studying. -- Not defining the actual variant of TSP that you worked on. For example, **Euclidean TSP** specifies "vertices on the plane" using (x,y) coordinates, and the distance between vertices is then calculated using Pythagoras Theorem. You then also need to check this version is still NP-hard, and cite a reference to confirm this fact. -- The given definition of TSP suggests optimising **time**, when it should be optimising **cost** (sum of weights). -- Confusing "problem definition" with "algorithm/solution method". - - **Problem**: gives a description of the encoding of a problem, and then asks for property. - For TSP: this is "given a weighted complete graph … find the shortest cycle." - - **Algorithm**: a step by step mechanism that we can use to program a computer to use the problem's description and recover the required property. - This is usually described using pseudocode, and then implemented in real code. -- It is more accurate to refer to TSP as "computational (optimisation) problem" rather than "mathematical problem". -- Define number of nodes in graph to be N but then use n later. (Symbols are case sensitive.) -- In the literature, a graph G=(V,E) is specified by sets V of vertices and E of edges. V and E are **not** numbers - they are sets. -- Using N for both the "set of nodes" and its size. -- Mistakes in understanding the meaning of NP-hard. -- Mistakenly stating that the **optimisation version** of TSP is in NP. It's not because it is not a **decision problem**. NP only contains **decision** problem - nothing else! -- Justifying NP-hardness by reducing TSP to another NP-complete problem, when it should be the other way round. -- Stated that exhaustive search is inefficient but did not say why. -- Exhaustive search costs O(n!), not O((n-1)!). - # Methodology - Methodology not stated explicitly in the text, e.g. parameters of generation, what is measured and what is averaged. @@ -74,12 +53,6 @@ - Time without units (e.g. seconds or minutes?) - Accuracy without units (e.g. percentage?) -# Reflection - -- Did not identify any transferable skills or knowledge gained from the project. -- Identified some gains but did not specify exactly how they will help in the future. -- Identified some weaknesses but did not give concrete suggestions on how to improve them. - # References - Not referencing the first paper that proved a fact, e.g. that TSP is NP-hard.