OpenAI (ChatGPT), gives different numerical answers to the same question based on the same dataset

Questions
1

Describe the problem/error/question

I have a workflow that uses the AIAgent node to analyse data in a Google sheet. I use gpt-5.2 as AI. The question I ask is : Ccount the number of rows where username is “hogeschool_vhl” and the Date is not empty. I have two scenario’s : One i which i directly put this prompt into the node. The other scenario is where I read exactly the same prompt from another sheet and place that prompt into the prompt field of the AIAgent node. The same dataset used in both scenarios. Both scenario’s not only come up with the wrong number, but both numbers are alo wrong. What bothers me now is how come a same numerical question on the same dataset, results in a different answer. if I know how I can also post two screenshots showing the same prompt and a different answer.

What is the error message (if any)?

Please share your workflow

(Select the nodes on your canvas and use the keyboard shortcuts CMD+C/CTRL+C and CMD+V/CTRL+V to copy and paste the workflow.)
{
  "nodes": [
    {
      "parameters": {
        "promptType": "define",
        "text": "={{ $json.Prompt }}",
        "options": {
          "systemMessage": "You are a helpful AI assistant . Provide clear, concise, and friendly responses in English. If asked for a number, only respond with the number.\nThe dataset to be used is in set: Sheet1 from the Google sheet:  Instagram_Posts.\nThe dataset is the result of scraping of Instagram account executed by Bright Data.\nThis is the data in the file:\nUsername : this is the username/ account name of the instagram poster\nDate : this is the date of the post\nPost: this is the actual post\nLikes : the number of likes the post has received\nNr comments: this is the number of comments made on the post\n\nIf the number of comments is larger than 0, in that case additional rows are added with fields:\nUsername: the username/ account to which a comment is made\nDate :Kept empty\nPost: Kept empty\nLikes : Kept empty\nNr comments:Kept empty\nuser_commenting: the username/ account that made a comment\nLikes_of_Comments: the number of likes of that comment.\n"
        }
      },
      "id": "4d6caf91-1ef4-494e-9491-d5dc37548cd7",
      "name": "AI Agent1",
      "type": "@n8n/n8n-nodes-langchain.agent",
      "typeVersion": 3.1,
      "position": [
        128,
        -64
      ]
    },
    {
      "parameters": {
        "model": {
          "__rl": true,
          "value": "gpt-5.2",
          "mode": "list",
          "cachedResultName": "gpt-5.2"
        },
        "builtInTools": {},
        "options": {
          "timeout": 120000
        }
      },
      "id": "f861a7f8-5b2a-41ae-bde8-f7f3ab6d94fe",
      "name": "OpenAI Chat Model1",
      "type": "@n8n/n8n-nodes-langchain.lmChatOpenAi",
      "typeVersion": 1.3,
      "position": [
        16,
        176
      ],
      "credentials": {
        "openAiApi": {
          "id": "U16ZdfkT0Wm1cRyo",
          "name": "OpenAi account"
        }
      }
    },
    {
      "parameters": {
        "documentId": {
          "__rl": true,
          "value": "1MRzwapyMZMG0vnGoMx4fanRwfV-xtL5W9xunCuhdjwg",
          "mode": "list",
          "cachedResultName": "Instagram_Posts",
          "cachedResultUrl": "https://docs.google.com/spreadsheets/d/1MRzwapyMZMG0vnGoMx4fanRwfV-xtL5W9xunCuhdjwg/edit?usp=drivesdk"
        },
        "sheetName": {
          "__rl": true,
          "value": "gid=0",
          "mode": "list",
          "cachedResultName": "Sheet1",
          "cachedResultUrl": "https://docs.google.com/spreadsheets/d/1MRzwapyMZMG0vnGoMx4fanRwfV-xtL5W9xunCuhdjwg/edit#gid=0"
        },
        "options": {}
      },
      "type": "n8n-nodes-base.googleSheetsTool",
      "typeVersion": 4.7,
      "position": [
        320,
        192
      ],
      "id": "e0dd802d-396f-461b-81c9-9daf6e20b314",
      "name": "Get row(s) in sheet in Google Sheets",
      "credentials": {
        "googleSheetsOAuth2Api": {
          "id": "i5ZDOao1fR8d2f3v",
          "name": "Google Sheets account"
        }
      }
    },
    {
      "parameters": {},
      "type": "n8n-nodes-base.manualTrigger",
      "typeVersion": 1,
      "position": [
        -432,
        -64
      ],
      "id": "94aa7517-c7e4-4e57-8383-e5733ddcb03c",
      "name": "When clicking ‘Execute workflow’"
    },
    {
      "parameters": {
        "documentId": {
          "__rl": true,
          "value": "1MRzwapyMZMG0vnGoMx4fanRwfV-xtL5W9xunCuhdjwg",
          "mode": "list",
          "cachedResultName": "Instagram_Posts",
          "cachedResultUrl": "https://docs.google.com/spreadsheets/d/1MRzwapyMZMG0vnGoMx4fanRwfV-xtL5W9xunCuhdjwg/edit?usp=drivesdk"
        },
        "sheetName": {
          "__rl": true,
          "value": 53746632,
          "mode": "list",
          "cachedResultName": "AI Analysis",
          "cachedResultUrl": "https://docs.google.com/spreadsheets/d/1MRzwapyMZMG0vnGoMx4fanRwfV-xtL5W9xunCuhdjwg/edit#gid=53746632"
        },
        "filtersUI": {
          "values": [
            {
              "lookupColumn": "Include",
              "lookupValue": "1"
            }
          ]
        },
        "options": {}
      },
      "type": "n8n-nodes-base.googleSheets",
      "typeVersion": 4.7,
      "position": [
        -192,
        -64
      ],
      "id": "3fe968af-34e5-46b6-a61b-7f005cb36260",
      "name": "Get row(s) in sheet",
      "credentials": {
        "googleSheetsOAuth2Api": {
          "id": "i5ZDOao1fR8d2f3v",
          "name": "Google Sheets account"
        }
      }
    },
    {
      "parameters": {
        "operation": "update",
        "documentId": {
          "__rl": true,
          "value": "1MRzwapyMZMG0vnGoMx4fanRwfV-xtL5W9xunCuhdjwg",
          "mode": "list",
          "cachedResultName": "Instagram_Posts",
          "cachedResultUrl": "https://docs.google.com/spreadsheets/d/1MRzwapyMZMG0vnGoMx4fanRwfV-xtL5W9xunCuhdjwg/edit?usp=drivesdk"
        },
        "sheetName": {
          "__rl": true,
          "value": 53746632,
          "mode": "list",
          "cachedResultName": "AI Analysis",
          "cachedResultUrl": "https://docs.google.com/spreadsheets/d/1MRzwapyMZMG0vnGoMx4fanRwfV-xtL5W9xunCuhdjwg/edit#gid=53746632"
        },
        "columns": {
          "mappingMode": "defineBelow",
          "value": {
            "row_number": "={{ $('Get row(s) in sheet').item.json.row_number }}",
            "Include": "0",
            "Date modified/added": "={{ $now }}",
            "Result": "={{ $json.output }}"
          },
          "matchingColumns": [
            "row_number"
          ],
          "schema": [
            {
              "id": "Include",
              "displayName": "Include",
              "required": false,
              "defaultMatch": false,
              "display": true,
              "type": "string",
              "canBeUsedToMatch": true
            },
            {
              "id": "Date modified/added",
              "displayName": "Date modified/added",
              "required": false,
              "defaultMatch": false,
              "display": true,
              "type": "string",
              "canBeUsedToMatch": true
            },
            {
              "id": "Prompt",
              "displayName": "Prompt",
              "required": false,
              "defaultMatch": false,
              "display": true,
              "type": "string",
              "canBeUsedToMatch": true,
              "removed": true
            },
            {
              "id": "Result",
              "displayName": "Result",
              "required": false,
              "defaultMatch": false,
              "display": true,
              "type": "string",
              "canBeUsedToMatch": true
            },
            {
              "id": "row_number",
              "displayName": "row_number",
              "required": false,
              "defaultMatch": false,
              "display": true,
              "type": "number",
              "canBeUsedToMatch": true,
              "readOnly": true,
              "removed": false
            }
          ],
          "attemptToConvertTypes": false,
          "convertFieldsToString": false
        },
        "options": {}
      },
      "type": "n8n-nodes-base.googleSheets",
      "typeVersion": 4.7,
      "position": [
        480,
        -64
      ],
      "id": "b0559cb9-51db-4e6a-8b4f-bffa394eb97e",
      "name": "Update row in sheet",
      "credentials": {
        "googleSheetsOAuth2Api": {
          "id": "i5ZDOao1fR8d2f3v",
          "name": "Google Sheets account"
        }
      }
    }
  ],
  "connections": {
    "AI Agent1": {
      "main": [
        [
          {
            "node": "Update row in sheet",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "OpenAI Chat Model1": {
      "ai_languageModel": [
        [
          {
            "node": "AI Agent1",
            "type": "ai_languageModel",
            "index": 0
          }
        ]
      ]
    },
    "Get row(s) in sheet in Google Sheets": {
      "ai_tool": [
        [
          {
            "node": "AI Agent1",
            "type": "ai_tool",
            "index": 0
          }
        ]
      ]
    },
    "When clicking ‘Execute workflow’": {
      "main": [
        [
          {
            "node": "Get row(s) in sheet",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Get row(s) in sheet": {
      "main": [
        [
          {
            "node": "AI Agent1",
            "type": "main",
            "index": 0
          }
        ]
      ]
    }
  },
  "pinData": {},
  "meta": {
    "templateCredsSetupCompleted": true,
    "instanceId": "a256caaf927d8b6fecd66012f15459060ec2fca55c23cb3757c0092517d4e8b9"
  }
}

Share the output returned by the last node

Information on your n8n setup

  • n8n version:
  • Database (default: SQLite):
  • n8n EXECUTIONS_PROCESS setting (default: own, main):
  • Running n8n via (Docker, npm, n8n cloud, desktop app):
  • Operating system:
2

Hello @Jitse_Schaafsma You should remove the Google Sheet Nodes and add these instead : , Google sheet Update row(s) - tool and Google sheet Append row (s) - tool. Then prompt your AI Agent to use them separatedly according to the tasks, for example if you want the AI Agent to check for specific infos from the sheet you should prompt it to use the Google sheet get Row (s) - tool to read the sheet and so on.

Wish you good luck !!

3

This is expected behavior for an AI agent when you are counting.

Your question may be numeric but the agent is still using a Large Language Model. It gets to determine how to use the GSheets tool, that includes how many rows to fetch as well as how to interpret your dataset. Two runs can produce different results because the process is not deterministic.

There are also invisible differences that can show up when loading a prompt(line breaks, spacing, encoding) and this can change how the model interprets information.

When trying to return an exact count don’t use AI but n8n logic like:

-Google Sheets node with filters

-Filter items in n8n

-Then count with {{$items().length}}

AI is more for analysis and interpretation, not so much for deterministic counting.

4

Hi @Jitse_Schaafsma As i can see in your workflow you have not added a calculator in the AI agent as a tool as this is considered the best practice and saves computational cost, below is the workflow you should be considering:

Hope this helps.

1 Like
5

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