> ## Documentation Index > Fetch the complete documentation index at: https://docs.nora.my/llms.txt > Use this file to discover all available pages before exploring further. # Clusters overview > Confirmed failures grouped by cause. Experiments start here A **cluster** is a group of signals the Failure Agent has confirmed and grouped by cause. A single signal is one data point; a cluster is a pattern worth fixing. Experiments in Simulation also start by picking a cluster. If you have no clusters yet, confirm signals in [Signals](/reliable/signals/overview). Confirming a signal seeds the first cluster. Clusters list. Status chips and date and agent filters above a table with Pattern, Flow, Signals, Cases, Severity, and Status columns ## The list view Open **Clusters** in the sidebar to see the workspace's clusters as a table. * **Pattern** the cluster's summary title, generated by Nora from a representative signal * **Flow** which Flow the failures came from * **Signals** how many signals are grouped * **Cases** how many cases have accumulated (see [Cases](/reliable/clusters/cases)) * **Severity** * **Status** Open, Improving, or Resolved Filter from the top of the page. * **Search clusters** * Date range: All time, Last 7 days, Last 14 days, Last 30 days, Last 90 days * Agent: **All agents** or a specific agent * Status chips: **All**, **Open**, **Improving**, **Resolved** (each chip shows a count) ## Cluster detail Click a row to open the cluster. The header shows the title along with a category tag (for example tool failure or ungrounded claim), the status, and the case count, source-signal count, and Flow. The body is the case table (see [Cases](/reliable/clusters/cases)). You can also arrive from the signal side: **View parent cluster** in a signal's detail opens the cluster that signal belongs to. ## Managing folders Clusters are managed like folders. * **New folder** at the top right of the list creates an empty cluster folder. * The ⋯ menu on the detail page offers **Rename**, **Merge into…**, and **Delete folder**. * Deleting a folder does not delete its cases; they move to Unclustered. ## Starting an experiment from a cluster **Run simulation** at the top right of the detail page starts a new experiment with this cluster already selected (see [New experiment](/reliable/simulation/new-experiment)). ## Learn more The inputs and expected answers a cluster accumulates. Experiments are scored against them. Three steps from picking a cluster to launch. Confirm signals to grow clusters. The cluster-level experiment board.