Test of Variability Thinking sample from paper "An Instrument for Measuring Variability Thinking"

1 TEST OF VARIABILITY THINKING (TVT) OBJECTIVE OF THE TEST TEST OF VARIABILITY THINKING (TVT) is designed to assess an individual’s ability to reason about variable configurations. The test measures the ability to identify optional and alternative components, understand constraints and dependencies, validate configurations, anticipate the consequences of changes, and compare variants within a modular system. Inspired by Software Product Line Engineering (SPLE) practices, the TVT provides a structured way to assess variability reasoning skills in both educational and research contexts. CONTENT 10 questions with 4 options each, with only one correct answer. ESTIMATED TIME 15 minutes. MAXIMUM HONESTY IS REQUIRED. THIS IS AN ANONYMOUS QUESTIONNAIRE. Genre * Age? * Have you ever played with Playmobil? * Have you ever designed a customized product or configuration (for example, by choosing parts, colors, or accessories)?* What level of knowledge of configurability and/or variability do you think you have? (1 – none, 10 – expert) * 2 Introduction Welcome to the product configuration test. Imagine you work in a store that sells sets inspired by the world of Playmobil. Each set can be composed of different pieces, characters, and accessories, and each customer may request a different combination depending on what they want to recreate: a castle at war, a forest camp, explorers, dragons, aerial defenses, and many other elements. As in any modular system, not all pieces can be freely combined. Some elements require others in order to be assembled, certain accessories share the same assembly point, and some options only make sense if specific components are included. Your task is to analyze these relationships and decide which combinations are possible, which configurations are valid, and what changes would be needed to satisfy the customer’s request. In each question, you will be presented with a small scenario. A customer wants a specific set, the store wants to launch a new product, or there is a need to decide how to document a combination of pieces. Your goal is to choose the option that best respects dependencies, assembly constraints, and reuse criteria among the elements. You do not need prior knowledge of variability. Just follow the logic of which pieces fit together and which do not. Shall we begin? 3 Sample question This test consists of several questions with four options, only one of which is correct. Below, you will be shown a description accompanied by images and a final question. In this case, the correct option is b) (the second one). Make sure to select it. As owners, we have decided to sell different types of castles: basic (1), medium (2), and complete (3). In addition, we also offer the possibility of adding a dragon with rider to the castle (4). Question: If we add the dragon with rider, what is the final number of possible sets that I can offer? a) It will be the same b) It will increase c) It will decrease d) It is not possible to add a dragon 4 Question 1/10 We offer three types of castles: basic (1), medium (2), and complete (3). In addition, we allow soldiers to be added individually, meaning the number of soldiers can be 0, 1, 2, 3 (4), or even more. If more than 3 soldiers are added, then the castle cannot be basic. With 4 or more soldiers, only the medium and complete castles are available. Question: With these options —castle type + freely chosen number of soldiers— we want to know what happens to the total number of possible combinations that we can offer: a) It will be the same b) It will increase c) It will decrease d) It is not possible to add a dragon 5 Question 2/10 (This question is independent of the previous one.) Now, in the store, we offer different types of animals: bears (1), geese (2), and fish (3). A new animal has arrived, the mouse (4), which is very popular on social media, and therefore we have decided that all our sets must include mice. However, we will never include mice together with bears. Question: By introducing mice, the final number of possible sets that I can offer: a) It will be the same b) It will increase c) It will decrease d) It is not possible to add mice 6 Question 3/10 (This question is independent of the previous one.) In the items we offer, we have always worked with three types of elements: kitchen utensils (1), tools (2), and other objects (3). These three groups defined all possible combinations so far. From this year on, we have decided to expand the catalog by incorporating a new element: a laptop (4). The laptop is not mandatory and does not automatically appear in all sets; instead, it becomes another option that the customer may choose to include or not, just like the rest of the elements. With this expansion of options, we want to know what happens to the total number of possible configurations. Therefore, we ask the following question: Question: By adding the laptop as a new selectable option, the final number of possible sets that we can offer: a) It will decrease b) It will increase c) It is not possible to add a laptop d) d) It will be the same 7 Question 4/10 (This question is independent of the previous one.) In our catalog, we have added three medieval elements: a tower (1), a dragon (2), and a wall (3). These elements cannot be combined freely: the tower can never appear on its own, because it always requires a wall (4), and the dragon cannot be sold separately either, because it only makes sense if there is a tower (5). The wall, on the other hand, can appear on its own. Question: With these rules in mind, which combinations could be offered as valid options in the store? a) The tower and the dragon b) The wall, the tower, and the dragon c) The wall and the dragon d) All of them are correct 8 Question 5/10 (This question is independent of the previous one.) In our catalog, we work with three figures that fit within the same scene: the bear (1), the salmon (2), and the fisherman with his fishing rod (3). The bear is an independent element: it can appear in a set without the salmon, although if the salmon is present, both can interact (4). The salmon is also part of the environment and is important for the fisherman. Unlike the bear, the fisherman does require the salmon to exist, because it is precisely what he fishes (5). Without the salmon, his presence would lose its meaning. Recently, we added a new element: the cave. In this case, the cave is mandatory for the bear to appear; whenever there is a bear, there must also be a cave (6). A staff member proposes removing the salmon from the catalog. He argues that, since the bear already has the cave as a required element, the salmon “is no longer needed”. The question is: if we remove the salmon, would we be making a good decision, or would we be breaking important relationships between the elements? a) Yes, because the cave and the bear form a complete set without the need for the salmon b) No, because removing the salmon would break important relationships with the bear and the fisherman c) Yes, because having or not having the salmon does not affect the other options d) No, because the salmon is more visually appealing to the customer 9 Question 6/10 (This question is independent of the previous one.) A customer enters the store with a very specific idea. He wants to recreate the scene of a castle under attack. His goal is to build a scenario in which the castle has to defend itself against a major siege. In our catalog, we have several characters and elements that could appear in this scene: The castle, which is what needs to be defended. (1) The enemies, who are the ones actually attacking the castle. (2) The dragon, which lives nearby but only participates in a siege if explicitly included; it may appear… or not. (3) The villagers, who simply live there. They are peaceful and do not take part in the defense. (4) If we want to fulfill the customer’s dream exactly, we need to include the minimum necessary to recreate it: the castle and someone to attack it. Question: With this in mind, which of the following sets represents that minimum requirement? a) Castle, enemies, and dragon b) Castle, villagers, and enemies c) Castle, enemies, villagers, and dragon d) Castle and enemies