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Decentralized Reputation in OpenBazaar - OpenBazaar

Ratings and Reviews

Initially, OpenBazaar will support ratings for Vendors (including the product/service they sell) and Moderators, who play a crucial role in the trust infrastructure of the network.

We expect that in the early days of OpenBazaars release, Moderators will need to leverage their external reputation to gain trust from users on the network. This represents a unique opportunity for groups such as BitRated to extend their services into a decentralized markeplace.

Rating a Vendor

As mentioned earlier, the rating model for Vendors is comparable to eBay and TaoBao, and thus leverages the user experience most e-commerce users are familiar with.

Vendors will be rated in 5 categories:

  1. Feedback rating
  2. Item/content/service quality
  3. Item/content/service listing description
  4. Item/content/service delivery
  5. Customer service

Each rating criteria will be rated out of 5 stars.

Unlike eBay and TaoBao though, the meaning of these stars are not left open to subjective interpretation, but reflect an objective assessment criteria in order to more accurately standardize Buyer ratings.

In addition to these ratings, the Buyer can also write a text review of the transaction.

Feedback Rating

What was the overall feedback when purchasing the product from the Vendor?

Item/Content/Service Quality

What was the quality of the item, content, or service from the vendor?

Item/Content/Service Listing Description

How accurate was the listing description of the item, content or service?

Item/Content/Service Delivery

How quickly was the item sent, content accessible, or service performed after ordering?

Customer Service

How do you rate the quality of the Vendors communication?

Text Review

Similar to eBay, written reviews have a size limit of 80 characters.

Making a Rating

Ratings are made in the last stage of the trade flow (see above; Stage 4 Buyer Receipt). When a user receives an item, they need to confirm that the item was received in order to release funds from escrow to the Vendor. During that process, they will be asked to make a rating and write a text review as described above.

While the data is stored within the trade receipt, it isnt efficient (and doesnt scale) to download a Vendors entire trade receipt history just to extract the rating and review data for that user (or for an item they sell).

Instead of a trade receipt, Vendors will serve transaction summaries that contain the relevant data to validate a transaction and calculate the reputation score.

The schema of a transaction summary is:

{
  "tx_summary" : {
      "vendor" : {
        "guid" : "",
        "pubkey" : ""
      },
      "transaction" : {
        "listing" : "",
        "bitcoin_address" : "",
        "price" : "",
        "buyer_pubkey" : "",
        "moderator_guid" : "",
        "moderator_pubkey" : ""
      },
      "vendor_tx_signature" : "",
      "txid" : "",
      "trade_receipt_hash160" : "",
      "rating" : {
        "feedback": 0,
        "quality" : 0,
        "description" : 0,
        "delivery_time" : 0,
        "customer_service" : 0,
        "review" : ""
      }
  },
  "buyer_signature" : ""
}

One of the most important elements of the transaction summary is the vendors signature of the transaction object, which contains the listing hash, bitcoin address, price etc. When the Buyer places the initial order with the Vendor, the Vendors client will send a digital signature of the transaction object. This will be a cryptographic proof of the Vendors involvement in the trade, which is necessary before any rating is madeotherwise a Vendor could refuse to attribute themselves to a transaction summary with a negative rating.

The rest of data such as transaction ID (txid), the trade receipt hash, the rating and review text is added at the conclusion of the transaction and sent to the Vendor for their records. The transaction summary can also be sent to the Moderator for storage, in case the Vendor omits summaries with negative ratings.

Overall, the transaction summary is a more compact proof of the Vendor and Buyers exchange and subsequent rating than the entire trade receipt. Future releases will address the issue of long term storage of transaction summaries and Vendor transparency, potentially with technologies such as Blockstore and/or IPFS.

Rating a Moderator

Rating a Moderator for their service is significantly more complex task. To our knowledge, it is entirely without precedent. Users should expect this area of reputation to evolve as we learn what transpires over the network in the years to come. Below we describe a system we feel comfortable launching and learning from.

The task of Moderation is to pick a winning and losing side from a dispute between two parties (the Vendor and Buyer). Unfortunately, the rating of a Moderator will be heavily biased depending on whether the user has won or lost the dispute.

In other words, if the Moderator decides that you are the winner in a dispute, you are more likely to rate the Moderator positively for their wise and noble decision. The opposite is true if you are on the losing side.

As a result, OpenBazaar must show the rating/reviewfor each disputed transactionfrom both sides. The goal is to highlight any potential agreement between the winner/loser in the rating criteria.

Moderators will be rated in 4 categories:

  1. Feedback Rating
  2. Dispute Resolution Listing Description
  3. Resolution Time
  4. Customer Service

As with Vendors, each rating criteria will be rated out of 5 stars. Each star has an objective meaning that will be displayed to the user. Users can also submit a text review of the Moderator.

Feedback Rating

What was the overall feedback to the Moderator?

Dispute resolution listing description

How accurate was the Moderator's dispute resolution description service?

Dispute resolution time

How quickly was the dispute resolved by the Moderator?

Customer Service

How do you rate the quality of the Moderators communication?

Text Review

Written reviews have a size limit of 80 characters.

Making a Rating

Broadly speaking, there are 2 classes of dispute that may arise:

  1. The Buyer failing to release funds from escrow
  2. The Buyer being unsatisfied with the contents or delivery of the item

Dispute: The Buyer failing to release funds from escrow

This scenario will be due to the Buyer being incapacitated or forgetting to release funds. If the Buyer fails to respond after a reasonable number of attempts over time, the Moderator will collaborate with the Vendor to release the funds.

This process is initiated by the Vendor, who flags a dispute to the Moderator and Buyer (if online). To flag the dispute, the Vendor sends the dispute claim (with a digital signature) to the Moderator and Buyer:

  1. The hash of the transaction object
  2. Who the claimant is (i.e. the Vendor in this example)
  3. The written claim (80 characters long)

If the Buyer fails to respond to the Moderator, the Moderator will issue their resolution. The resolution, digitally signed by the Moderator, will include:

  1. The hash of the dispute claim
  2. The written resolution outcome and justification (character length to be decided)

The resolution is then sent to both the Vendor and Buyer (if online) and a transaction releasing the funds from escrow to the Vendor is created and signed.

A transaction summary is automatically generated at the end of this process, as described earlier, that also includes the dispute claim, the resolution, and the Moderator review.

Both the Vendor and Moderator will host and serve this transaction summary to other users.

Vendor transaction summary

{
  "tx_summary" : {
      "vendor" : {
        "guid" : "",
        "pubkey" : ""
      },
      "transaction" : {
        "listing" : "",
        "bitcoin_address" : "",
        "price" : "",
        "buyer_pubkey" : "",
        "moderator_guid" : "",
        "moderator_pubkey" : ""
      },
      "vendor_tx_signature" : "",
      "txid" : "",
      "trade_receipt_hash160" : "",
      "dispute" : {
        "transaction_hash160" : "",
        "claimant" : "",
        "claim" : ""
      },
      "claimant_signature" : "",
      "moderator_resolution" : {
        "dispute_hash160" : "",
        "summary" : ""
      },
      "moderator_signature" : "",
      "vendor_rating" : {
        "feedback": 0,
        "quality" : 0,
        "description" : 0,
        "delivery_time" : 0,
        "customer_service" : 0,
        "review" : ""
      },
      "moderator_rating" : {
        "feedback" : 0,
        "description" : 0,
        "time" : 0,
        "customer_service" : 0,
        "review" : ""
      }
  },
  "buyer_signature" : ""
}

Dispute: The Buyer being unsatisfied with the contents or delivery of the item

This dispute will arise if the Buyer claims that the item was not delivered or if the item delivered was incorrect, damaged, or significantly different from the product description. Whatever the circumstance, the Buyer will be attempting to obtain a full refund.

Typically, the Buyer will be the one to initiate a dispute and submit a dispute claim to the Moderator and Buyer. After this step, most of the dispute resolution process will transpire over the internal messaging channel we have built into OpenBazaar, which is encrypted with the participants public keys.

After the Moderator has come to a decision to who the winning party is, they will issue a resolution as described above.

When the funds are finally released from escrow to the winning party, both the Buyer and Vendor can generate a transaction summary. Here they will both have an opportunity to rate the Moderator on the dispute resolution. The Buyers transaction summary will also have the rating/review of the Vendor, which may not be counted in the final reputation score of the Vendor if the Buyer lost the dispute.

The Moderator will host the transaction summaries from both parties, which will be available for users to inspect.

Buyer transaction summary

{
  "tx_summary" : {
      "vendor" : {
        "guid" : "",
        "pubkey" : ""
      },
      "transaction" : {
        "listing" : "",
        "bitcoin_address" : "",
        "price" : "",
        "buyer_pubkey" : "",
        "moderator_guid" : "",
        "moderator_pubkey" : ""
      },
      "vendor_tx_signature" : "",
      "txid" : "",
      "trade_receipt_hash160" : "",
      "dispute" : {
        "transaction_hash160" : "",
        "claimant" : "",
        "claim" : ""
      },
      "claimant_signature" : "",
      "moderator_resolution" : {
        "dispute_hash160" : "",
        "summary" : ""
      },
      "moderator_signature" : "",
      "vendor_rating" : {
        "feedback": 0,
        "quality" : 0,
        "description" : 0,
        "delivery_time" : 0,
        "customer_service" : 0,
        "review" : ""
      },
      "moderator_rating" : {
        "feedback" : 0,
        "description" : 0,
        "time" : 0,
        "customer_service" : 0,
        "review" : ""
      }
  },
  "buyer_signature" : ""
}

Vendor transaction summary

{
  "tx_summary" : {
      "vendor" : {
        "guid" : "",
        "pubkey" : ""
      },
      "transaction" : {
        "listing" : "",
        "bitcoin_address" : "",
        "price" : "",
        "buyer_pubkey" : "",
        "moderator_guid" : "",
        "moderator_pubkey" : ""
      },
      "vendor_tx_signature" : "",
      "txid" : "",
      "trade_receipt_hash160" : "",
      "dispute" : {
        "transaction_hash160" : "",
        "claimant" : "",
        "claim" : ""
      },
      "claimant_signature" : "",
      "moderator_resolution" : {
        "dispute_hash160" : "",
        "summary" : ""
      },
      "moderator_signature" : "",
      "moderator_rating" : {
        "feedback" : 0,
        "description" : 0,
        "time" : 0,
        "customer_service" : 0,
        "review" : ""
      }
  },
  "vendor_signature" : ""
}

Reputation Score

The reputation score of a Vendor is the average feedback rating from all of their transactions. A user can expand the reputation score to see a Vendors average ratings for item quality, listing description, delivery time, and customer service.

The reputation scores of a Moderator are the average feedback ratings from the winning and losing sides of disputed transactions. As with the Vendors, the average ratings for each criteria can be expanded from both sides.

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