Two marks Questions with Answers

Two Marks Questions with Answers

Q.1 How will you measure the problem solving performance?  AU: May-10

Ans.: Problem solving performance is measured with 4 factors.

1) Completeness - Does the algorithm (solving procedure) surely finds solution, how if really the solution exists.

2) Optimality - If multiple solutions exist then do the algorithm returns optimal amongs them.

3) Time requirement.

4) Space requirement.

Q.2 What is application of BFS.

Ans.: It is simple search strategy, which is complete i.e. it surely gives solution if solution exists. If the depth of search tree is small then BFS is the best choice. It is useful in tree as well as in graph search.

Q.3 State on which basis search algorithms are choosen.  AU: Dec.-09

Ans.: Search algorithms are choosen depending on two components.

1) How is the state space - That is, state space is tree structured or graph? Critical factor for state space is what is branching factor and depth level of that tree or graph.

2) What is the performance of the search strategy? A complete, optimal search strategy with better time and space requirement is critical factor in performance of search strategy.

Q.4 Evaluate performance of problem solving method based on depth-first-search algorithm.  AU: Dec.-10

Ans. DFS algorithm performance measurement is done with four ways

1) Completeness - It is complete (gurantees solution).

2) Optimality - It is not optimal.

3) Time complexity - It's time complexity is O(b).

4) Space complexity - It's space complexity is O(b ^d+1).

Q.5 What are the four components to define a problem? Define them.

AU: May-13

Ans.: The four components to define a problem are,

1. Initial state - It is the state in which agent starts in.

2. A description of possible actions - It is the description of possible actions which are available to the agent.

3. The goal test - It is the test that determines whether a given state is goal rup (final) state.

4. A path cost function - It is the function that assigns a numeric cost (value) to each path. The problem-solving agent is expected to choose a cost-function that reflects its own performance measure.

Q.6 State on what basis search algorithms are choosen?

(Refer Q.3) AU: Dec.-09

Q.7 Define the bi-directed search.

Ans.: As the name suggests bi-directional that is two directional searches are made in this searching technique. One is the forward search which starts from initial state and the other is the backward search which starts from goal state. The two searches stop when both the searches meet in the middle.

Q.8 List the criteria to measure the performance of search strategies.

(Refer Q.3)AU: May-14

Q.9 Why problem formulation must follow goal formulation?

Ans.: Goal based agent is the one which solves the problem. Therefore while formulating problem one need to only consider what is the goal to be achieved so that problem formulation is done accordingly. Hence problem formulation must follow goal formulation.

Q.10 Mention how the search strategies are evaluated?  AU: Dec.-16

Ans.: Search strategies are evaluated on following four criterion,

1. completeness: does the search strategy always find a solution, if one exists?

2. time complexity: how much time the search strategy takes to compute.

3. space complexity: how much memory consumption search strategy has ?

4. optimality: does the search strategy find the highest-quality solution? Define admissible and consistent heuristics.

Q.11 Define admissible and consistent heuristics.  AU: Dec.- 16

Ans.: Admissible heuristic: A heuristic is admissible if the estimated cost is never more than the actual cost from the current node to the goal node.

Consistent heuristic: A heuristic is consistent if the cost from the current node to a successor node, plus the estimated cost from the successor node to the goal is less than or equal to the estimated cost from the current node to the goal.

Q.12 What is the use of online search agent in unknown environment. AU: Dec.-16

Ans.: Online search agents operate by interleaving computation and action: first it takes an action, and then it observes the environment and computes the next action. Therefore in unknown environment they became useful as the action is taken first then the environment is observed.

Also, online search is a necessary idea for an exploration problem, where the states and actions are unknown to the agent.

Q.13 List some of the uniformed search techniques.  AU: May - 17

Ans.: The uninformed search strategies are those that do not take into account the location of the goal. That is, these algorithms ignore where they are going until they find a goal and report success. The three most widely used uninformed search strategies are,

1. Depth-First Search - It expands the deepest unexpanded node.

2. Breadth-First Search - It expands the shallowest unexpanded node.