Why the Fibonacci Sequence Works Well for Estimating. Sometimes, story points even encourage agile anti-patterns! To improve estimation practices and avoid the pitfalls of story points, I hosted a round table discussion with Mike Cohn, John Cutler, Andrea Fryrear, Troy Magennis, and Dave West. Once you attempt to translate story points into a cost (e. Getting Started: 3 Affinity Estimation Methods. Story Points specify an unknown time range. 1. Estimators will ask for clarification and briefly discuss the impact areas, development methodology, etc. It protects a team against themselves or the. Enquanto a maioria das equipes estima a dificuldade de uma tarefa pelo tempo (metade do dia, uma semana ou um mês), os story points são um método para medir o esforço em uma escala relativa. How Do Story Points Work? In the Agile framework, a project’s functionality, described from the perspective of what a user can do, is known as a “story. (average story points delivered over the last few sprints) the whole scrum team should provide the estimate, not just one person, so the score. Priority 1 - Features that have been reviewed and agreed upon by the full ITS Leadership Team as top priorities for the department and individual teams. 1,2,3,5,8,13,21 also called Story Points Fibonacci agile points; These arbitrary units of measurement for user stories convey the team’s difficulty or complexity level. The most common story-pointing system is arguably Mike Cohn’s modified Fibonacci sequence, where each value is a non-linear function of preceding values. Story points are actively used in Scrum and other Agile methodologies, replacing the traditional way of estimating with money and time. Story Point nên được ước lượng được theo dải. 8 = 7* (10 - 2)*0. Agile teams use estimation to forecast their velocity and productivity. When a team adjusts the reference PBI’s every sprint, the velocity of different Sprints is no longer comparable. Here is why I am not convinced with Story points. Then the spreadsheet formula, working from the agile story point estimations, will auto-populate the corresponding hours from the Parameters tab. The uncertainty in the estimation is captured in the Story Point Fibonacci-like sequence itself: 1, 2, 3, 5, 8, 13, 20, 40, 100. you get it. Essentially, the Agile Fibonacci scale gives teams a more realistic way to approach estimates using story points. Development teams often benefit from the focus that a sprint goal provides. Fibonacci. again rather than actually using retro to improve the agile and. So user story points ideally define the complexity and efforts involved to design,. Story points are an Agile estimation technique that gives you a relative estimate of how much work and effort will go into a particular task. The Fibonacci Story Point system has been around for a while, but the recent adoption of agile practices has made it popular again. Choose an estimation tool for the team to use, something like Planning Poker, Miro board, or similar. When we use the Fibonacci series in estimating these gaps. Story point estimation is the process of assigning story points to a product backlog item or a user story. A Story Points Scale encompasses a spectrum of potential values that agile teams use to gauge the size of a user story. Story points help agile teams compare different user stories and prioritize them according to their value and feasibility. Why use the. Story points are a relative measure of the effort and complexity required to complete a task or user story in agile software development. If you’re having problems with estimation, sprint planning, or agile story points, you can always run a Parabol. Each estimation is modified just for the sake of easiness of use of 20,40,80 and 100. Net Capacity of an Agile Team. At first, all the team can estimate using their intuition and first impressions of the task. Our Agile/Scrum team follows the Fibonacci sequence for story point estimation. Use one of three default scales for estimating Story Points: Fibonacci sequence, 5 fingers and t-shirt sizes. I think story points for a task is in fibonacci so that it can be decomposed into two (or more) smaller sub-tasks with appropriate story point. He suggests imagining holding a one-kilogramme weight (2. The 13-point card should be used for any story the team estimates larger. You may wonder what Fibonacci has to do with agile? The most common estimation method is story points, a technique based on the Fibonacci sequence. That’s all there is to it. The benefit of Fibonacci is that each number is roughly 60% greater than the previous one (with the obvious exception of 1 and 2, of. We estimate stories like below-: 1 story point= Simple. Therefore, story points are neither complexity (too difficult to determine), nor effort (we don’t want to compare time with time), but somewhere in between. 2 story points= Medium complexity. Yes, the story points in agile takes a notion of time contrary to what we can read sometimes. Fibonacci Sequence for Story Point Estimation. Points just show how much more effort each work is RELATIVE to others. Developers use a fibonacci sequence: 0, 0. 3. Learn how to use the Fibonacci sequence to estimate the complexity and effort of user stories in Agile planning. Instead, they estimate the difficulty of the task. An inside look into secrets of agile estimation and story points. After the discussion, each estimator selects a card with a specific story points Fibonacci number. The Fibonacci scale is a series of exponentially increasing numbers used to estimate the effort required to complete a task or implement a user story . The fibonacci sequence is a popular scoring scale within some teams. however the industry standard and to keep the practice uniform within, team, organization, or even in the Agile world we use the points in Fibonacci series i,e, 1,2,3,5,8,13,21,…Fibonacci series numbers have relative differences from each other. To see this, consider the team that is trying to decide between estimating a story as either three or five. It’s Composed Of Integers. Agile teams typically use the Fibonacci Sequence, a variant of it, or T-shirt sizes. See how we teach and use relative sizing with t-shirt sizes and Fibonacci points to estimate. For velocity to make sense. Add a new animation to the drop-down menu is 2 story. g. Difficulty could be related to. Story points are a unit of measure for expressing an estimate of the overall effort that will be required to fully implement a product backlog item or any other piece of work. Using Fibonacci sequence numbers. However, it is not clear whether we should have any zero point stories at all. Moreover, the Fibonacci sequence has a varying distance between Story Points. 3. Story points are often used in a modified Fibonacci sequence to indicate the higher variance with larger efforts. 2-3h -> 1 point. All include a Question card and a Pass card. It can be used in almost. Pengertian Story Point. One approach is to have the team start out with a medium-sized story, and agree on what value that represents. The actual numbers don’t matter — you could assign values between 1,000,000 and 5,000,000 if you want. The Scrum Master (moderator) shares the story. The factors under risks include Unclear demand, Dependence of the third party, and uncertainty in the future. The higher the number, the. ) or a modified Fibonacci sequence (1, 2, 3, 5, 8, 20, 40, etc. People are used to track projects using time units such as hours or days. For instance, the difference between 3 and 5 is 2, while the difference between 5 and 8 is 3. How Do Story Points Work? In the Agile framework, a project’s functionality, described from the perspective of what a user can do, is known as a “story. If you are not using Fibonacci series, you may end up comparing which story is bigger twice or 4 times relative to another story, the idea is to have user stories with the lower points. Story points give more accurate. Instead, story points express the amount of effort needed to complete a task compared to other work in the sprint. Some people will not fully get the Fibonacci based story points. Agile teams use the Story Point estimation matrix to show the complexity, risks, uncertainty and difficulty of the User Story. Optimiser votre vélocité agile en estimant vos story points. . Scenario 2 : Let. Create a Story Point Scale. Agile Tools by Corrello allows you to add story points and WIP Limits to Trello. Some teams use the 't-shirt sizes' to estimate, Small, Medium, Large, XLarge. . 3. Using points is one version of what is often called "Relative sizing. Share. Create a Story Point Scale. The Fibonacci sequence is a series of numbers that is often used in agile software development to assign story points to user stories. The product backlog is where requirements are stored on an Agile project in the form of user stories. 5 k = n/2 + 1. Step #4: When asked by Tia, each. 24/08/20. Team's composition should remain stable for a sufficiently long. So the sequence will be 0. Estimating Stories. In story points estimations, the team doesn’t estimate the exact time needed to implement the functionality. Using the Fibonacci sequence for agile story point estimation. This is an abstract measure of the effort that a team requires to implement the user story. Some teams use a linear scale (1, 2, 3, etc. Velocity. Let the team discuss final thoughts or questions about the story. Story points account for factors like task complexity and uncertainty, which makes them more accurate than other estimation techniques such as time-based estimation. Even though 5 ideal man hours is precise, it's probably not any more accurate than 0. Story points help agile teams compare different user stories and prioritize them according to their value and feasibility. Estimate agile effort or relative size of user stories, also known as story points, or complexity. Hence, the estimation in hours is subjective, whereas the estimation in story points is objective, wherein three means a particular level of complexity for all the team members. If you’ve ever done agile estimating with story points or used Planning Poker ®, you may have used either the Fibonacci sequence or a modified Fibonacci sequence. One common methodology for employing agile story points is to assign values to backlog items using the Fibonacci sequence — 1, 2, 3, 5, 8, 13, 21. Complexidade (em story points), esforço (em horas) e prazo (em dias) dependem do sequenciamento destas user stories que entrarão na esteira do time ágil. Giving ‘2’ provides you the room to give a smaller story ‘1’ if discovered at a later stage. 15. The fibonacci sequence is used by Scrum teams for story point estimates – 1, 2, 3, 5, 8, 13, 21, and so on. Let’s recall why we essentially use story points: to assess if a team will be able to get the work done in a sprint. The traditional Fibonacci sequence is 1, 2, 3, 5, 8, 13, 21 and so on, with each number the sum of the preceding numbers. In this article, my focus is on shar ing my experience as a Trainer/Mentor/Coach to Agile teams with respect to Agile estimations; and on using the Fibonacci sequence as scale to size the Story. Once the stories are ready, the team can start sizing the first card it considers to be of a “smaller” complexity. Story Points specify an unknown time range. -1 story point for your team might not equal the same amount of effort involved in 1 story point for another team. Agile story points, combined with user. If the team wants to map the sizes to a number system (to calculate velocity or the number of points they can close per Sprint), they simply replace small with 1 and medium with 2 and so on. It is the most effective way to get a clear understanding of the work. The sprint sizing is in the form of story points based on a task’s. Ceux-ci sont utilisés pour représenter la taille, la complexité et l’effort nécessaire pour réaliser ou mettre en œuvre une user story. As soon as the estimators are done assessing the user story, they reveal their cards at the. You cannot say one point equals such-and-such number of hours. While constraining your story points to a scale based on the Fibonacci sequence can help teams estimate efficiently, some teams prefer doing away with number-based estimation altogether. The team can then estimate the user story by discussing its complexity and assigning a corresponding number of estimation points to it. For me this is exactly why we use storypoint (fibonacci) instead of time estimations. Fibonacci Sequence (1, 2, 3, 5, 8, 13, 21) for Evaluation Story points are an estimation technique used in Agile project management methodologies to help your team scope the effort required to complete a task. Story points are team specific. They evaluate product development efforts by referring to three development aspects: the amount of work required by the product. When the meeting starts, Tia hands out the deck of cards to each estimator or each estimator opens the planning poker card app on their smartphones. Many simplify the numbers to “1, 2, 3, 5, 8, 13, 20, 40, and 100. You're saying that "the old complexity plus the complexity you just discovered" is the same. Check out this one: Agile-Estimation-Poker-Cards-Fibonacci — only ranges until 21. Burnup chart:. Fibonacci, Power Of Two and T-Shirt Card Decks; Unlimited Participants; Free Trial Sign Up. Does the use of the Fibonacci Series - in Agile Estimating and Planning - lead to more ACCURATE estimates?Download your FREE CHEAT SHEET: Agile product development, a reference story serves as an aid for a team to estimate the effort required for the work of a user story that is actually to be processed. Play story points planning poker. Story points. Using this estimation methodology, agile teams organize work items from the highest to the lowest priority to decide where to focus their time and efforts. We can’t divide by zero, so our Job Size estimation should start from 1. Difficulty could be related to complexities, risks, and. As Maarten Dalmijn points out in his article, the smaller an item of work, the lower the level of uncertainty. Agile Scrum is based on the concept of working iteratively in short sprints, typically two weeks long, where the requirements and development are continuously being improved. Embracing story points as part of your Agile process will help you adapt to changes and. It is not limited to Scrum only, but as Scrum is the most popular Agile framework, it is often mentioned together with Scrum (so will this article). ”. You would achieve 12. These estimations are based on the entire group’s input and consensus, making them more engaging and accurate than other methods. Ideally, using the Fibonacci series, the story point estimate should be much more obvious to the team, since one story point could be almost. Muchos desarrolladores en entornos de metodología Agile han logrado mejorar el proceso de estimación usando la escala de Fibonacci o una sucesión de Fibonacci modificada para estimar el trabajo que se necesita completar en una iteración. risks and uncertainties that might affect development. In Agile, story points represent the complexity and effort needed to accomplish a user story. The reference story is a user story whose requirements, complexity and implementation are comprehensible to all team members. Story point estimation is a technique used in Agile project management to replace task estimation in time or money. The Golden Rule of Agile Estimation: Fibonacci Story Points Arjun Kudinoor July 19, 2023 Abstract In the agile methodology of project management, software development teams often use an idea called story points to quantify the effort it takes to complete user stories, like a feature or an application. The development team meets to discuss impediments towards its progress in achieving the sprint goals. Check out the Trello blog. What Are Agile Story Points? Dec 7, 2022 Don’t Equate Story Points. 4. Typically, numbers from the Fibonacci sequence (1, 2, 3, 5, 8,…) are used for this purpose. The team can then start estimating other user stories by comparing them to the reference user story. It should drive the Team’s discussion and understanding of a requirement. That's why many agilists prefer unitless story points as a task size measure. One of the concepts new scrum teams struggle with is how to relate story points and hours. amount of work is the result of multiplying the story’s Fibonacci complexity by a linearly. To me, story points are a effective way to learn how to prepare work by breaking it down into manageable pieces. Fibonacci series is just one of those tools. Because story point values are generally chosen from fibonacci numbers (or an alternative. Story Points Scale. Story points are relative and are measured against a baseline or benchmark. Try to keep most estimates, or at least the most important estimates within about one order of magnitude, such as from 1-10. Typically, numbers from the Fibonacci sequence (1, 2, 3, 5, 8,…) are used for this purpose. Eventually, you’ll get a baseline of small (1pt), medium (3pts), and large (5pts) size stories for the project. Unfortunately, story points are often misused. For a team of 7 developers you would have over 20-40 user stories which is likely way too many. When doing this, the relative size of a story is the focus. They are used to estimate the complexity and size of a feature or user story, and are a way of expressing the level of uncertainty associated with that estimate. use the Fibonacci series (1, 2, 3, 5, 8). Wait up, not just that!Agile story points scale. The Fibonacci scale is a series of exponentially increasing numbers used to estimate the effort required to complete a task or implement a user story . เมื่อได้ Story Point ตุ๊กตาไว้แล้ว เราจะเริ่มนำเล่น Poker Planning โดยเริ่มจาก User story. Such sizing can be done in time or story points – a measurement unique to agile, which is based on a task’s expected complexity, the amount of work required, and risk or uncertainty. It. Story Point is a popular measuring unit used by Agile practitioner. The scale is unique to the team as each. The Fibonacci sequence is quite popular for making accurate estimates in agile projects. 1. The larger the number, the more intricate the task and the more effort it will demand. When we estimate with story points, we assign a point value to each item. How It Works: Determine Point Scale: Decide on a sequence of numbers representing the complexity or size of tasks. Teams use this sequence, rather than a linear 1 – 10 as it forces them to provide a relative estimate. A complexidade em story points é a estimativa para que o time encaixe as user stories na capacidade (Capacity x Load). They’re usually expressed as a number. Introduction. Let's have a look at the initial values for better. Chaque story point se voit attribuer un nombre sur la suite de Fibonacci. Hint: If you are new to story points, please take a look at The relative side of Agile: using story points for estimations. The table below suggests different ways of estimation that can be mapped to Story points using the Fibonacci. We're one of the fastest growing power-ups of 2022. Setiap tim dalam sebuah projek memberikan nilai poin berdasarkan kompleksitas, jumlah,ketidakpastian pekerjaan, dan. The higher the number, the more complex the story point, and presumably, the. You may wonder what Fibonacci has to do with agile? The most common estimation method is story points, a technique based on the Fibonacci sequence. While Story Points include effort, like absolute estimating, it further. For software developers, it's among the most difficult — if not the most difficult — aspects of the job. In simple terms, a story point is a number that tells the team about the difficulty level of the story. Relative complexity is easier to judge than a. An hour 2 –. Frank, the team’s scrum master, has cleared space on a long section of wall in the team room, and now the team assembles in front of it. Many agile teams, however, have transitioned to story points. In this note, different systems of. Using Story Points in Agile and Scrum Sprint Planning. We will use the following definition for story points: Story points represent the complexity of a story in relation to its effort. They are the tool to determine the velocity of teams. ) composed of any positive real number. . I think you have something when you suggest getting something written down and shared about what a 1,2 or 5 point ticket might look like. 8. But in agile development, the Fibonacci sequence is usually modified to start from 0. Say I assigned 21 story points to a task. Every member is given a deck of cards and the product manager or owner gives an overview of the particular user story or backlog item to start. The most common system for using Story Points is through the use of a Fibonacci sequence. These metrics will help you improve your planning in the long run. In other words, a story that’s assigned 2 story points should be twice as heavy as a story assigned 1 story point. Ceux-ci sont utilisés pour représenter la taille, la complexité et l’effort nécessaire pour réaliser ou mettre en œuvre une user story. The “poker” aspect of the name refers to the cards that. Why Should Teams Use Story Points in Agile? Story points in Agile benefit development teams and product owners alike. Say the feature is actually 200 story points (consists of 2, 3, 5, 8 pointer stories). The raw values we assign are unimportant: Some teams use a modified fibonacci sequence (1, 2, 3. Each number is the sum of the two preceding numbers. Team's composition should remain stable for a sufficiently long. Story points are a unit of measure for expressing an estimate of the overall effort that will be required to fully implement a product backlog item or any other piece of work. In this article, Keith Richards, the Founder of agileKRC, and the Lead Author of Agile Project Management (AgilePM) discusses the big flaw of the Fibonacci sequence and how that effects agile estimating using tools such as Planning Poker to estimate story points. For estimating the time it takes to complete tasks, you want a scale that is made of integers. The cards are revealed, and the estimates are then discussed. you get it. An agile estimation tool should be able to adapt to your reality and set you in the center of control. Story points can help prevent teams from burning out at work. The mapping is rarely straightforward. ). Consider using the Fibonacci number sequence. Post the story: The previous command opens a dialogue box. Make sure you’ve broken down tasks into smaller units before estimating. Story points are perhaps the most misunderstood topic in agile. Though the estimate could be for another type of task, such as a bug fix. and is the perfect Power-Up for Scrum or Kanban teams using Trello (or even teams blending a mix of. One way to clearly define story points is to use the Fibonacci sequence rather than a linear scale. Story points in Scrum often use a standard or modified Fibonacci sequence to estimate the level of effort for stories based on some agreed-upon baseline such as a "typical" one-point story. As a rule, if a task is obviously too big to fit into one sprint, you should always break it down into smaller components. Agile teams often use the Fibonacci sequence to estimate the “size” of tasks and user stories for their upcoming sprint. Story points – Points are used to assign each engineering task a set amount of time. Story points are units of measure for expressing an estimate of the overall effort required to fully implement a product backlog item or any other piece of work. Many simplify the numbers to “1, 2, 3, 5, 8, 13, 20, 40, and 100. User story points allow you to quickly estimate the work involved in each item on your backlog, and how much work you can get done in a sprint or release. But its estimate is not based on it and this notion of time is not materialized by 1 story point = 1 day. As you probably know if you’re reading this article, the term “story points” comes from the idea of user stories, a key idea within Scrum and Agile project management methodologies. Use Fibonacci or a modified Fibonacci series for estimates. Trying to correlate a story point to time is a Scrum/Agile anti-pattern and is not a good practice. Story points are a unit of measurement for estimating the effort required to complete a work item on the backlog. Velocity is the term used to describe this ratio of story points. Using story points, a team could, for instance, estimate using a combination of risk, uncertainty, complexity and effort for the entire team. . After choosing an agile estimation technique, team members have to create a story point scale. If the story is bigger than the agreed limit (8, 13, or more) then it should be split into smaller stories. Write these numbers on post-it notes or cards. The raw values we assign are unimportant: Some teams use a modified fibonacci sequence (1,. dev is a free online Scrum poker tool (similar to Planning Poker ) for remote agile teams. Story point estimates are relative, often using the Fibonacci scale (1, 2, 3, 5, 8, 13, 20, 40+) for relative sizing. They estimate the effort to build a product by addressing three aspects of development: the amount of work the product requires. Story Point unit is defined by the scrum team; every scrum team defines its. Story Points as a Fibonacci sequence. In affinity estimation, each story is grouped according to similar complexity. User stories , the smallest units of work in Scrum, are collected and managed by a product owner during sprint planning and backlog grooming . Compare jobs (three features, in this example) for each CoD component and job size using a simple table or spreadsheet (Figure 5). The whole process starts with a set of product features in scope. dev is a free online Scrum poker tool (similar to Planning Poker ) for remote agile teams. Linearly increasing by a constant number: 5, 10, 15, 20, 25, 30, 35. The Fibonacci sequence is one popular scoring scale for estimating agile story points. -The amount of effort involved in 1 story point should remain stable for your. Gives a Sense of Objectivity: If a developer can complete one story in 5 hours, the same 5 hours can be either two or seven for the other. 1. The Fibonacci. Difficulty could be related to complexities, risks, and. The smallest tasks are estimated at 1 point and then other tasks are weighed and estimated in accordance with that task. Sprint Poker: Minimize bias and boost precision 🃏. Designed to create a sustainable development pace and provide more realistic deadline expectations for stakeholders, agile estimation techniques use relative sizing rather than predicting real-time estimates. When we estimate with story points, we assign a point value to each item. In simple terms, Scrum Epic in Agile Methodology is a big chunk of work that can be divided into smaller user stories, which we can think of like a new project or a new big module in the project. Then, label the y-axis on your Fibonacci scale template with “risk” and the x-axis with “effort. You can use a tool like Mountain Goat Software's Velocity Range Calculator to perform the following formula: Assuming n observations, the formula for calculating a 90% confidence is given by. Keep Estimates Manageable. Each number is the sum of the two preceding. Story points are used to represent the size, complexity, and effort needed for. Irgendwann kam auf, dass man mit Story Points eigentlich Komplexität schätzt. instead of t-shirt sized buckets or story points. Easier to ask ‘is that a. Determine the scale to be used for assigning story points. Agile Tools by Corrello. So, I can create 2 sub-tasks with story points 8 and 13. Teams use t-shirt sizes, the Fibonacci sequence, or planning poker to make proper estimations. 1, 2, 3, 5, 8, 13, 21, 34, 55… This sequence helps give a sense of scale. I also explained why agile teams. 1. Most teams use the Fibonacci sequence to represent agile story points. -Points will mean different things to different teams or organizations. To use the Fibonacci sequence for story sizing, start by assigning the smallest story in your backlog a point value of 1. 2. Story Points and Fibonacci. 2. T-shirt sizes make for a quick and universally-understood. Fibonacci sequence and Planning Poker. Story points - Công cụ ước lượng của Agile. Enquanto a maioria das equipes estima a dificuldade de uma tarefa pelo tempo (metade do dia, uma semana ou um mês), os story points são um método para medir o esforço em uma escala relativa. The team loses information you can no longer use the historical velocity to plan ahead. 8. In order to make an accurate estimation of story points, there are a few things to keep in mind: How to measure story points: the Fibonacci sequence. It is fully integrated with Corrello Scrum and Kanban Charts. Enter command: Type /storyplan followed by the story title to create an agile story for estimation. Chaque story point représente une période. There are several ways of estimating story points, and the two most common ways are by using the Fibonacci sequence, and by using the planning Poker method. Just as hours and man/days, Story Points are numerical values. Chaque story point se voit attribuer un nombre sur la suite de Fibonacci. The Fibonacci sequence is the numbers you get when you start with 1 and 2, and then each subsequent number is the sum of the previous two. Post-agile have an issue in converting points to hours, and pre-agile people struggle to visualize effort in points because many of them haven’t done that. The scale of measure requires the story points to be assigned appropriately. This web tool harnesses the power of the Fibonacci Sequence, making Agile estimation intuitive and efficient. Story points are a relative measurement of how difficult a task is. The Fibonacci Agile Story Point Sequence: The most popular and widely acclaimed scale used to determined Story Points is the "Fibonacci Agile Estimation Scale". When a team adjusts the reference PBI’s every sprint, the velocity of different Sprints is no longer comparable. But don’t worry. Ví dụ dãy các bội số của 2 (1, 2, 4, 8, 16,…), hoặc dãy số Fibonacci (1, 2, 3, 5, 8, 13,. For our imaginary team, the story point sequence will mirror the classic Agile methodology adaptation of Fibonacci: 0, 0. Der Sinn von Schätzung ist, die Entscheidung “soll ich es überhaupt machen” zu ermöglichen. One of the first things a Dev team should do is set their scale through affinity estimating. 2. Story points are not directly linked to a specific unit of. I think story points for a task is in fibonacci so that it can be decomposed into two (or more) smaller sub-tasks with appropriate story point. The higher the number, the more complicated the story point will be. Free-scale slider voting allows arbitrary estimation. For example, a team might use a Fibonacci sequence (1, 2, 3, 5, 8, 13, etc.