The evaluation process of student's title Chapter Mastery Rate

Design Introduction

Judging the condition of Mastering the Students ' Chapter mastery by the result of students ' doing the problem

The degree of student Mastery is calculated from the experience value, and the required experience value is exp_end.
Mainly by the number of students to do the problem and the result of the decision, the higher the goal, the higher the amount of questions to practice.
Students in the system to do the problem, each do N road titled a group, each group arrived at the lowest correct rate after P_min began to calculate the experience, the lowest added to become exp_min, to achieve the highest correct rate P_max added to the maximum of Exp_max, with the most direct through the correct rate p_end, After reaching the experience value is full to master (when there are cross-group pairs, it is also considered to satisfy the direct pass condition). The number of groups satisfying the midpoint correct rate of p_mid reached a sufficient number of M is determined to be cumulative master. Whether you do the right or wrong, each problem you do increases the experience value Exp_did.

Target	Mastering Levels	number of topics per group	minimum correct rate per group	highest correct rate per group	each group directly through the correct rate	midpoint correct rate	Mastering the number of groups needed to reach the correct midpoint rate	the difficulty of practicing a topic
One	learn	5	50%	90%	100%	80%	2	varies by chapter
a	understanding	5	50%	90%	100%	80%	3	varies by chapter
one	apply	5	50%	90%	100%	80%	3	varies by chapter
Two this	learn	5	50%	90%	100%	80%	2	varies by chapter
Two this	understanding	5	50%	90%	100%	80%	2	varies by chapter
two	apply	5	50%	90%	100%	80%	1	varies by chapter

Initial positioning

The result of the test volume score determines the student's initial experience value, which has been done in the system by default in several groups titled standards. If need more accurate, then can be by the student test paper to do the result related, such as: a problem does wrong to represent a Chapter Mastery degree is not high.

The

Initial score	Understanding how many groups have been completed	understand how many groups have been completed	number of groups that the app has completed
120-150	2	2	1
100-119	1	1	0
0-99	0	0	0

Interpolation score Conversion

The experience value is exp_end (take 600 number larger convenient small step, can be divided by the smaller prime number to divide easily), the midpoint correct rate group M is the minimum required number of steps. A linear change of the maximum and minimum correct rate is made by the p_mid turning point at the midpoint correct rate.
In order to achieve the goal of the use of the degree of difficulty mastery for example, the midpoint of the correct rate of 80%, the required number of steps is 3, each student to do the correct rate of the group reached 80%, the experience value increased by 600/3 = 200 points. The minimum correct rate is 50%, and when the minimum setting is 50, the correct rate increases (a-50) * (200-50)/(80-50) + 50 (when a=60, the XP value increases by 100). a%<80% When the correct rate is a%>90%, the maximum XP value is increased by 300.

Based on the target level of the maximum experience, the remaining target levels are decremented.

Difficult levels have an impact on low difficulty. Understanding level has 100% effect on understanding level, and application level has 30% effect on understanding level.

Mastery Rate needs product performance for the initial time, the closer to full improvement is slower, the mastery rate on the basis of experience is worth multiplying by a power function to meet the requirements. The formula is degree = norm * exp^r, wherein degree is the mastering rate; norm is normalized coefficient, so degree is in a certain interval; R is the power factor. Data Structure Data Sheet statistics of Students ' mastery degree

CREATE TABLE tb_student_mastery_degree
(
  ID BIGINT () PRIMARY KEY not NULL auto_increment,
  student_id BIGINT () COMMENT ' student ',
  chapter_id BIGINT (COMMENT ' chapter '),
  section_id BIGINT ' section, can be empty, denoted as this record as Chapter mastery rate ' ,
  difficulty INT COMMENT ' corresponds to understanding hierarchy (understanding, Understanding, Application) ',
  degree DOUBLE COMMENT ' mastering rate ',
  exp INTEGER COMMENT ' experience value ',
  Latest_prolems varchar (+) COMMENT ' recent array record n, configurable ',
  problem_results varchar (COMMENT ') to do the results, record M-bar, configurable ',
  created_dt datetime,
  updated_dt datetime,
  version INT (one) DEFAULT ' 0 '
);

CREATE UNIQUE INDEX Un_student_section_diff on Tb_student_mastery_degree (student_id, section_id, difficulty)

Chapter Configuration table (the problem requires difficulty, each chapter requires configuration)

CREATE TABLE tb_student_mastery_degree
(
  ID BIGINT () PRIMARY KEY not NULL auto_increment,
  chapter_id BIGINT (COMMENT ' chapter ',
  section_id BIGINT () COMMENT ' section, can be empty, expressed as this record for the chapter mastery rate ',
  layer INT COMMENT ' corresponds to the understanding level (understanding, understanding, Application) ',
  difficulties VARCHAR (COMMENT ' Meet the difficulty list of topics ',
  over_count DOUBLE COMMENT ' Mastering the number of groups needed to reach the correct rate of midpoint ',
  created_ DT datetime,
  updated_dt datetime,
  version INT (one) DEFAULT ' 0 '
);

Configuration Parameters

The empirical value algorithm, for each different level, the number of questions per group N, the midpoint of the correct rate P_mid, each group reached the midpoint of the correct rate of the topic increased experience exp_mid; the lowest correct rate p_min, the lowest correct rate increases the experience value exp_min; maximum correct rate p_max, The maximum correct rate of experience is increased exp_max, the correct rate of the desired midpoint of the group M, directly determined to grasp the correct rate of p_end; cross-group connected to the number of required topics Allow_combo, regardless of the value of each problem added exp_did experience;

Downward influence, understanding level to understand inf21, apply level to understand level inf32, apply level to understand inf31;

Mastering degree and empirical value algorithm, the formula is degree = norm * exp^r, wherein degree is the mastery rate; norm is normalized coefficient, so degree is in a certain interval; R is the power factor. Program Structure The main process input students to do the problem record pre-processing necessary information, topics or students related through the topic section to obtain relevant student mastery records to determine whether the state to reach the number of groups, if not achieved, record the title information, experience value plus the topic experience. If the number of requests is reached, the correct rate of grouping is calculated and converted into empirical value. The experience value increases, translates into the mastery rate. Store a new student record. class Structure Process Control class Engine

The evaluation process that controls the degree of mastery of the entire student chapter calls different methods. Topic Information Preprocessing class Problempre

Preprocessing the topic into a VO empirical value calculation class containing all necessary input information expcalculator

Input the title information and the student's previous record, obtains this experience value Mastery degree judgment Class Degreedeterminer

Convert experience values to mastering degrees

End