Methods and systems of testing software, and methods and systems of modeling user behavior

A computer-implemented method of testing software executable by a computing device, the method comprising:

• traversing a state graph that models software, the state graph having multiple nodes, individual ones which represent a state, and links between the nodes that represent actions, the traversing using a first algorithm having a first graph traversal characteristic to produce a sequence of test actions, wherein the first algorithm having the first graph traversal characteristic is selected from a group of algorithms comprising:
• a random walk algorithm, a random destination algorithm, and an anti-random walk algorithm;
• traversing the state graph using a second algorithm having a second graph traversal characteristic that is different from the first graph traversal characteristic to produce a further sequence of test actions, wherein the second algorithm having the second graph traversal characteristic is different from the first algorithm having the first graph traversal characteristic and is selected from a group of algorithms comprising:
• a random walk algorithm, a random destination algorithm, and an anti-random walk algorithm;
• and operating on a software model using the first algorithm and the second algorithm to produce the sequence of test actions, the first algorithm being configured to randomly select a destination in then software model and move to that destination to produce the sequence of test actions, wherein the operating comprises using the first algorithm to select a destination node at random, independent of a nearest neighbor node, and traversing state space to arrive at the destination node, where the first algorithm is the random destination algorithm.

A computer-implemented method of testing software executable on a computing device, the method comprising:

• selecting a first algorithm from among a number of different algorithms, wherein the first algorithm is selected from a group of algorithms comprising:
• a random walk algorithm, a random destination algorithm, and an anti-random walk algorithm;
• operating on a software model that describes a behavior of software that is to be tested, the operating taking N steps using the first algorithm, where N is an integer and the steps produce a sequence of test actions;
• selecting a second algorithm from among the number of different algorithms, the second algorithm being different from the first algorithm, wherein the second algorithm is selected from a group of algorithms comprising:
• a random walk algorithm, a random destination algorithm, and an anti-random walk algorithm;
• and
• operating on the software model by taking N1 steps using the second algorithm, where N1 is an integer, the N1 steps producing an additional sequence of test actions, wherein the operating comprises using the second algorithm to select a destination node at random, independent of a nearest node, and traversing state spaces to arrive at the destination node, wherein the second algorithm is the random destination algorithm.