MobLab
Guides
Aa

Matrix: Instructor Specified

Game Description

MobLab's Matrix game allow you to specify the payoff matrix for a two-player normal-form (i.e. simultaneous-move) game. Each player can have two to four actions, and the number of row actions need not be the same as the number of column actions. This game can be used to represent a wide variety of two-player interactions by simply modifying the payoff structure.

Players are paired, with one assigned the role of the Row player, and the other the Column player. If you specify multiple rounds, both pairs and player roles are fixed. After each player makes her choice in each round, outcomes are revealed, and players move to the next round.

Brief Instructions

The game screen is shown in Figure 1. In addition to specifying the number of actions for each player and payoffs in each cell, you can specify the name of each action and the text that appears on the rules page of the player’s game screen.

Figure 1: Game Screen

Key Treatment Variations

Repeat play often results in markedly different outcomes than one-shot interactions.

To have each pair interact repeatedly, set Minimum Rounds > 0. For indefinite repetition, once Minimum Rounds has been reached, Ending Probability establishes the likelihood of proceeding to another round conditional on reaching the current round.

For one shot play, set Minimum Rounds to 1 and keep Ending Probability at 100. To have students play multiple rounds with re-pairing between rounds, click Replay after a one-round game. Choose Random to randomly assign both roles and partners in the next game.

Results

The results screen presents graphs, a table, and raw data, each focusing on the likelihood of defect or cooperate.

Figure 2: View Menu

Use the View menu (Figure 2) to choose between the different results tabs. If you used one of the Replay options, you can contrast the results between these linked games using the Compare button. To obtain a screen shot of the results, you can use the Download button beneath the compare button.

At the top of the Graphs tab, we depict the payoff matrix (Figure 3). This may be helpful in establishing the multiple equilibria in pure strategies.

Figure 3: Payoff Matrix
Figure 4: Action Frequency

Select the Graphs tab to show the payoff matrix and the action frequencies. The graphs display the frequency of each choice and each choice pair each outcome for each round (Figure 4). You can reveal or hide the results for an action by clicking the box next to an action in the legend.

Figure 5: Outcome Frequency

Next, using the Tables tab, we display again the payoff matrix and the frequency of each outcome for each round as well as the frequency total for all rounds played (Figure 5).

Figure 6: Raw Data

Finally, the Raw Data tab presents a player table with each player's choice, their group, and the round number in a table format. This table presents the data from the game that has not been processed in any particular way (Figure 6).

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