Interislander Ferry

Ranking Score Explained

Kia ora, thanks for your interest in how we calculate an experience's ranking score. It's at the core of Rankers so I'm pleased you're curious.

The ranking score percentage is used to compare and sort experiences in ranking tables. It is not necessarily a direct measurement of the quality of a particular experience as rated by its customers. I've found it a useful tool to allow me to find the best experiences with confidence. But I've also found it important to read the customer reviews before making any final judgements!

We calculate an experience's ranking score using a multi-factor data model instead of a raw data average (mean). This model takes into account several important questions. For instance - is there a trusted body of reviews? What is the age of a review and is the review from a credible source?

Below you'll find details around some of the important factors that went into calculating the ranking score for Interislander Ferry.

If you have any questions or comments about our ranking score calculation please get in touch at info@rankers.co.nz. We don't believe this is perfect or complete so we're always interested in ways we might make improvements.

Cymen Crick

Rankers Owner

Valid Reviews

349 Valid Reviews

The Interislander Ferry experience has a total of 360 reviews. There are 349 valid reviews that are included when calculating the ranking score and 11 invalid reviews that are excluded from the calculation. Reviews can be excluded only when a reviewer is not verified or after an investigation by our team determines the reviewer is not genuine.

Below is the distribution of ratings for the 349 valid reviews:

Rating	Count
10/10	40	11%
9/10	81	23%
8/10	103	30%
7/10	62	18%
6/10	29	8%
5/10	16	5%
4/10	7	2%
3/10	5	1%
2/10	2	1%
1/10	4	1%

77.13% Average

The raw data average (mean) for all the Interislander Ferry valid reviews is 77.13% and is based on 349 valid reviews. This value is not used to calculate the ranking score and it only provided here as a comparison to the weighted average.

Face-to-Face Reviews

309 Face-to-Face Reviews

The Rankers team meets with travellers while they’re in New Zealand and conducts face-to-face surveys. These reviews, in our opinion, are the most trusted in the industry and represent a critical control sample. To our knowledge, we are the only travel review website in the world that has gone to this extent.

More about face-to-face reviews

Within the 349 valid reviews, the experience has 309 face-to-face reviews collected during interviews by our team.

Below is the distribution of ratings for the 309 face-to-face reviews:

Rating	Count
10/10	30	10%
9/10	70	23%
8/10	98	32%
7/10	58	19%
6/10	25	8%
5/10	15	5%
4/10	6	2%
3/10	4	1%
2/10	2	1%
1/10	1	0%

77.22% Average

The raw data average (mean) for all the Interislander Ferry face-to-face reviews is 77.22% and is based on 309 face-to-face reviews. This value is not used to calculate the ranking score and it only provided here for comparison purposes.

Weighted Average

73.56%

Rankers calculates a weighted mean as a base average on which we can improve. Individual review's ratings are given a weight based on several factors. The weight of a review determines the overall impact it'll have on the final weighted average.

Recent reviews have more weight as they are more relevant and reflect the experience as it currently operates. Over time reviews become less relevant and loose their impact on the ranking score.

Low rating reviews carry slightly less weight. This dampens the effect of very low ratings for every experience across the board. This is especially important when the experience has few reviews overall and a single negative rating can grossly mischaracterise an experience. Consistent poor reviews will still result in the experience receiving a comparitively low ranking score.

Credible sources provide reviews that can be trusted. If we have verified a reviewer is genuine via a face-to-face meeting then the review carries additional weight.

Reviewer	Rating	Age	Relative Weight
Rina	9/10	104 days	100%
edm	1/10	378 days	38%
Colin Barrow	9/10	439 days	90%
Pauline	6/10	592 days	70%
Megan	5/10	744 days	53%
Marjolaine Loitz	4/10	774 days	44%
Keli Knox	10/10	1109 days	35%
Yar	1/10	1323 days	8%
Pinocity	6/10	1688 days	5%
Helen Russell	10/10	1869 days	5%
NewZealander	10/10	2143 days	4%
Tommy Pickett	9/10	2966 days	3%
Tom Bennett	8/10	2970 days	3%
Jeny Smolders	9/10	2972 days	3%
Gregg Wagstaff	7/10	3197 days	2%
Lianne Ijlst	8/10	3225 days	2%
Samantha and Neis	8/10	3226 days	2%
Brandon Cassidy	7/10	3242 days	2%
Vic Baughen	9/10	3244 days	2%
Anders Frank	7/10	3248 days	2%
Dina Schurer	8/10	3249 days	2%
Kim Youngsub	9/10	3250 days	2%
DEBBIE LAMBERT	10/10	3254 days	2%
Gary Williams	8/10	3254 days	2%
Kimberley Gardien	8/10	3261 days	2%
Antoine	9/10	3282 days	2%
Judit Van lanen	9/10	3287 days	2%
Bjorn Nielsen	8/10	3289 days	2%
Joel Virtanen	9/10	3291 days	2%
Corbin Hure	7/10	3291 days	2%
Ron	6/10	3294 days	2%
Thomas Simeon	8/10	3294 days	2%
Suzannah Hill	8/10	3295 days	2%
Kallan Mrozek	9/10	3296 days	2%
Kees Mol	9/10	3300 days	2%
Kristal Lavender	10/10	3300 days	2%
Bastian Bley	9/10	3301 days	2%
Jasmine Rogers	3/10	3302 days	1%
Louis Nilsson	8/10	3306 days	2%
Tim	7/10	3306 days	2%
Jendrik	6/10	3306 days	2%
Katharina	7/10	3307 days	2%
Chris Valchero	9/10	3310 days	2%
Rulp Niet	8/10	3312 days	2%
Soeren Buchheister	9/10	3313 days	2%
Chas Bronson	8/10	3313 days	2%
Jakob Lovdahl	9/10	3315 days	2%
Alexandra Schmidt	10/10	3325 days	2%
Jade Williams	10/10	3326 days	2%
Sam Staines	10/10	3327 days	2%
Nickolas Jonkergouw	7/10	3331 days	2%
Kirsty Smith	10/10	3331 days	2%
Eva Hesse	10/10	3346 days	2%
celine gries	8/10	3346 days	2%
tinagermany111	8/10	3360 days	2%
Cassandra Geyer	8/10	3545 days	2%
Olivier Reculeau	8/10	3546 days	2%
Thomas Michel	5/10	3547 days	1%
Lisa Haedrich	5/10	3551 days	1%
Nadja Guiliani	8/10	3555 days	2%
Elbrich	8/10	3555 days	2%
Jamie Serieux	7/10	3558 days	2%
Adele Jacques	9/10	3559 days	2%
Daniel Weber	6/10	3561 days	1%
Emily Noyd	8/10	3563 days	2%
Aparna Gula	10/10	3564 days	2%
Sebastiaan	7/10	3566 days	1%
Andre	9/10	3567 days	2%
Benedikt Hang	7/10	3568 days	1%
Yannick	8/10	3568 days	2%
S Black	9/10	3569 days	2%
Paul Larauze	6/10	3572 days	1%
Florence	6/10	3573 days	1%
Sarah Kovacs	8/10	3574 days	2%
Frenziska Schmid	7/10	3576 days	1%
Maud Livolsi	7/10	3583 days	1%
Lewis Whittle	6/10	3585 days	1%
Lukas Seager	6/10	3585 days	1%
Andrea Tabaka	8/10	3592 days	2%
Tina Rust	8/10	3594 days	2%
Joel Papak	8/10	3596 days	2%
Clemence and Pedro	9/10	3597 days	2%
Doms Wahlelr	9/10	3599 days	2%
Josef Biller	8/10	3599 days	2%
Justine Hoffmann	8/10	3600 days	2%
Friederike East	7/10	3600 days	1%
Mark White	10/10	3601 days	2%
Briony	8/10	3604 days	2%
Gabriel Siibers	8/10	3604 days	2%
Henry Wichler	8/10	3605 days	1%
Kyle Johnson	9/10	3607 days	2%
Niels Wezenberg	7/10	3608 days	1%
John Hamilton	9/10	3608 days	2%
Brianna Burd	9/10	3608 days	2%
Jessica Ruhland	8/10	3609 days	1%
Stula Vladimir	10/10	3610 days	2%
Cosmo Hartuna	7/10	3612 days	1%
Roland Fischer	6/10	3612 days	1%
Ross Holmes	9/10	3613 days	1%
Tilman	9/10	3615 days	1%
Petru	7/10	3616 days	1%
Fero Saarinen	6/10	3617 days	1%
Lauren Thompson	8/10	3619 days	1%
Meilin	8/10	3622 days	1%
Jonas Hoerning	10/10	3626 days	1%
Vanesha Patel	6/10	3627 days	1%
Mauricio Daniele	9/10	3627 days	1%
Sara and Antoine	8/10	3629 days	1%
Clare Pickford	6/10	3629 days	1%
Daniel Hill	10/10	3630 days	1%
Moritz Braun	7/10	3646 days	1%
Grischa Rodust	8/10	3653 days	1%
Chalie Dotesek	9/10	3654 days	1%
Julien Lafeville	7/10	3658 days	1%
Julia Huesam	8/10	3658 days	1%
Alexandre	9/10	3662 days	1%
Kev Zarka	6/10	3663 days	1%
Markus Wabing	8/10	3666 days	1%
Gessica	6/10	3699 days	1%
Simon Quass	9/10	3703 days	1%
Barthelemy	7/10	3932 days	1%
Brita Topp	10/10	4275 days	0%
Laim Thompson	8/10	4275 days	0%
Adriana	10/10	4283 days	0%
Pavel Jarolimek	5/10	4283 days	0%
Leonie Moeller	6/10	4284 days	0%
Doreen Gendel	8/10	4285 days	0%
Carla Oyarzun	3/10	4288 days	0%
Paolo Cases	3/10	4288 days	0%
Wolfgang and Christine	8/10	4293 days	0%
Helen	8/10	4306 days	0%
Olivier Carval	9/10	4308 days	0%
Hirsch Svenja	9/10	4309 days	0%
Mahr Svenja	8/10	4309 days	0%
Anna Guzewiez	9/10	4325 days	0%
Pier Durand	8/10	4329 days	0%
Serena Poggioli	9/10	4329 days	0%
Wayne Schist	7/10	4329 days	0%
Margreth Lydie	5/10	4337 days	0%
Laura Pleumeekers	7/10	4351 days	0%
David Brooks	10/10	4354 days	0%
Adrien Godeloup	9/10	4363 days	0%
Bet Dreno	8/10	4364 days	0%
Joachim	1/10	4365 days	0%
Pioter Jurkowski	7/10	4365 days	0%
Thomas Roche	9/10	4367 days	0%
Brian	9/10	4426 days	1%
hendrik king	9/10	4549 days	1%
Kiki Wykstra	5/10	4659 days	1%
Galen Licht	4/10	4659 days	1%
Yu-Ti Chu	7/10	4662 days	1%
Ton Martens	7/10	4662 days	1%
Joshua Perry	8/10	4667 days	1%
Molly Ladd	8/10	4667 days	1%
Michael Nolan	9/10	4671 days	1%
Julian Roots	9/10	4671 days	1%
Florent Corino	9/10	4675 days	1%
Amiot Cyriane	7/10	4675 days	1%
Annika	7/10	4675 days	1%
Jonas Herrmann	7/10	4675 days	1%
Matthieu Daveou	8/10	4675 days	1%
Julien Panossian	6/10	4675 days	1%
Raoul Montestruer	5/10	4675 days	1%
Alessa Ndra	8/10	4681 days	1%
Bjorn Hedmark	5/10	4682 days	1%
Evyatar Tulipman	7/10	4684 days	1%
S Curry	10/10	4699 days	1%
Ingrid	9/10	4743 days	1%
Reinier Timmer	7/10	4743 days	1%
Moorman	8/10	4752 days	1%
Stefan Roth	9/10	4777 days	1%
David	9/10	4791 days	1%
kevindang	10/10	4944 days	1%
Ruben Kunze	4/10	5026 days	1%
Sebastian Hol	9/10	5032 days	1%
Dick Stewart	8/10	5041 days	1%
David Beaumont	9/10	5048 days	1%
Beyeler	10/10	5053 days	1%
Nikita Sue	9/10	5058 days	1%
Schweiger	10/10	5060 days	1%
Jan & Marian	10/10	5139 days	1%
Konny	9/10	5143 days	1%
Waldemar Schuler	8/10	5143 days	1%
jule	3/10	5157 days	1%
Jack Potman	8/10	5359 days	1%
Jon_and_Family	9/10	5371 days	1%
Walker	9/10	5374 days	1%
Andreas Blessing	10/10	5382 days	1%
Gema	7/10	5385 days	1%
Avry Fabrice	6/10	5390 days	1%
Diane Johnston	9/10	5395 days	1%
Javier Munoz	8/10	5395 days	1%
Ben Akin-Smith	8/10	5396 days	1%
K Wallis	9/10	5401 days	1%
khs	9/10	5402 days	1%
Emma Ducat	9/10	5402 days	1%
Mr and Mrs Lambert	8/10	5409 days	1%
Andrew Koster	7/10	5415 days	1%
Bakker	8/10	5415 days	1%
Kimberly St Louis	8/10	5416 days	1%
Roel Wesstra	8/10	5422 days	1%
Seifert	10/10	5422 days	1%
Derek Woodward	9/10	5424 days	1%
Fabi & Sabi	8/10	5425 days	1%
Rosey834	8/10	5492 days	1%
Pete & Chris	10/10	5692 days	1%
Tony Masters	9/10	5755 days	1%
Hershell	8/10	5759 days	1%
Mike Robinson	9/10	5760 days	1%
Brent S	2/10	5761 days	0%
Zara Leyden	9/10	5769 days	1%
Judith	7/10	5773 days	1%
anon	8/10	5774 days	1%
Pierre Pilon	8/10	5775 days	1%
Jenny Omb	1/10	5780 days	0%
Frei Urs	6/10	5781 days	1%
Bryan Keddie	9/10	5791 days	1%
Leanne Rogan	5/10	5791 days	1%
Joanne Clarke	8/10	5795 days	1%
Wolfgang G	9/10	5801 days	1%
Thomas Signes	7/10	5822 days	1%
menzel	10/10	5840 days	1%
graemeh1	9/10	5841 days	1%
klinger	10/10	5841 days	1%
gereldineb	8/10	5851 days	1%
jennyb	9/10	5855 days	1%
Frank de Voogd	8/10	5861 days	1%
Jean Paul Mesnage	9/10	5867 days	1%
Hansjoerg Ehrmann	5/10	5868 days	1%
Daniel Alonso	9/10	5869 days	1%
Nigel Petrie	9/10	5880 days	1%
Tracy & Peter Cassidy	8/10	5896 days	1%
miniappleses	8/10	5918 days	1%
Josie Boyle	7/10	6029 days	1%
JanneP	9/10	6099 days	1%
Mikey	9/10	6106 days	1%
SablotniD	7/10	6110 days	1%
WiebkeS	9/10	6117 days	1%
Tanya	5/10	6118 days	1%
Jan	6/10	6118 days	1%
Viola	8/10	6120 days	1%
RowanL	7/10	6121 days	1%
VickiEngland	8/10	6129 days	1%
TomC1	8/10	6134 days	1%
AndyK	9/10	6134 days	1%
TatiamT	9/10	6134 days	1%
GillianK	8/10	6136 days	1%
EelcoK	9/10	6136 days	1%
Michael	9/10	6140 days	1%
soccaplaya14	10/10	6140 days	1%
Eugene	7/10	6142 days	1%
John	6/10	6144 days	1%
Tony	8/10	6149 days	1%
Middleton	4/10	6150 days	1%
Elise	8/10	6151 days	1%
Marie	8/10	6151 days	1%
ThomasS1	10/10	6156 days	1%
RasmusB	4/10	6158 days	1%
Simon	8/10	6163 days	1%
Phil&Joe	10/10	6165 days	1%
Marcus	7/10	6165 days	1%
Andre	7/10	6167 days	1%
Iris	9/10	6169 days	1%
Carla	7/10	6169 days	1%
Sandra	8/10	6173 days	1%
Schaffluber	10/10	6174 days	1%
Hayley	5/10	6175 days	1%
Con	2/10	6219 days	0%
felix	7/10	6220 days	1%
melissa	10/10	6226 days	1%
John B	5/10	6229 days	1%
Gemma	7/10	6267 days	1%
Henry	7/10	6268 days	1%
Antonella	10/10	6275 days	1%
Michelle	8/10	6275 days	1%
Laura	7/10	6284 days	1%
Sarah	8/10	6298 days	1%
Katerina	7/10	6319 days	1%
Erin	3/10	6319 days	1%
Mike Knight	9/10	6340 days	1%
Bronagh Mcartan	8/10	6349 days	1%
Dave	8/10	6360 days	1%
fgregory	10/10	6363 days	1%
Rhea	6/10	6409 days	1%
Georgina Mulligan	8/10	6421 days	1%
Karen C	7/10	6432 days	1%
Edmund Hillstone	10/10	6450 days	1%
Toby	6/10	6473 days	1%
Jennifer Baulch	9/10	6477 days	1%
Susan	8/10	6481 days	1%
Hoetnagels	7/10	6484 days	1%
Alan Bellerby	8/10	6487 days	1%
Sanne Jonker	7/10	6488 days	1%
Renske Tehurne	8/10	6492 days	1%
Benjamin Krein	7/10	6492 days	1%
Anne and Derek	8/10	6493 days	1%
James Davies	7/10	6493 days	1%
Naomi Horton	8/10	6494 days	1%
Roger Repolusk	8/10	6498 days	1%
Tony Wicks	6/10	6498 days	1%
Nancy Dol	8/10	6498 days	1%
Kristine	10/10	6498 days	1%
Kathy Hawey	9/10	6500 days	1%
David Buckley	8/10	6501 days	1%
Lena1	6/10	6501 days	1%
John Woodrow	8/10	6502 days	1%
Carmen Dolny	10/10	6502 days	1%
Haemnerli	8/10	6506 days	1%
Carla	8/10	6513 days	1%
Jim Curley	8/10	6513 days	1%
paulonline	7/10	6519 days	1%
Bex	6/10	6528 days	1%
Jenny Hulsebosch	8/10	6529 days	1%
Melissa Steedman	8/10	6540 days	1%
Tim	7/10	6541 days	1%
Falk Seidel	7/10	6544 days	1%
Hans Olthof	8/10	6544 days	1%
Anu	9/10	6547 days	1%
Anneli	6/10	6549 days	1%
purplekat99	10/10	6557 days	1%
Connor	10/10	6570 days	1%
Ad	7/10	6570 days	1%
Ann Westmacott	5/10	6575 days	1%
Paul Cowie	8/10	6576 days	1%
Ewen Maclean	8/10	6576 days	1%
Sarah Wilton	5/10	6576 days	1%
Arend v Dyn	7/10	6578 days	1%
Linda	8/10	6582 days	1%
Fiona	7/10	6582 days	1%
Ann	7/10	6583 days	1%
ranker_584	9/10	6586 days	1%
Christine	7/10	6586 days	1%
Nina	9/10	6586 days	1%
Anthony	7/10	6591 days	1%
Tom Clements	7/10	6591 days	1%
ranker_46	8/10	6703 days	1%
Pat Brewster	8/10	6703 days	1%
FrankOosterwijk	6/10	6788 days	1%
Kim	8/10	6788 days	1%
Helen	7/10	6819 days	1%
Heather	9/10	6819 days	1%
Helene	9/10	6831 days	1%
John	7/10	6831 days	1%
Giancarlo	6/10	6831 days	1%
Annette	4/10	6855 days	1%
John	5/10	6855 days	1%
Duncan	9/10	6860 days	1%
Jen	4/10	6871 days	1%
Rolf	8/10	6879 days	1%

Adjustments

Several adjustments to the weighted average are added to improve relevancy and credibility. These adjustments apply equally to all experiences that meet the criteria.

Sample Size Adjustment

No Adjustment

A reasonable number of reviews are necessary in order for the average to be credible and for an experience to take a prime position within the ranking tables. As such, experiences with only a few reviews have a moderated score. This does not mean that the experience or the reviews can't be trusted. The Interislander Ferry experience has plenty of reviews and does not meet the criteria for any adjustment.

Recent Reviews Adjustment

-1.93% Adjustment

There may be an adjustment if this experience hasn't received any reviews within the last 42 days. However the Interislander Ferry experience does not meet the criteria for any adjustment.

In addition, an experience's ranking score may be adjusted for each day there is no new ranking. After 1 day the adjustment comes into effect. The maximum number of days that can be adjusted for is 200 days. Due to the seasonal nature of many businesses, this adjustment is applied dynamically throughout the year.

The Interislander Ferry experience has been adjusted for 95 days. Adjustments are according to the following table.

Days	Adjustment
…	…
92	-1.87%
93	-1.89%
94	-1.91%
95	-1.93%
96	-1.95%
97	-1.97%
98	-1.99%
…	…

Balancing Adjustment

6.13% Adjustment

Every experience's review score is adjusted to balance out the disproportional number of negative reviews that are contributed.

You won't be surprised to learn that disgruntled customers are more likely to leave a review than happy ones. They are motivated to share their experience and warn others. We consider this a good thing and it's why reading the reviews is important. However we've learned it can misrepresent the experience in a more overall sense.

We apply a balancing adjustment to counteract this effect and ensure the ranking score is a more fair representation of the experience. This adjustment is applied equally to all experiences.

Final Ranking Score

78%

The final ranking score once any adjustments, ratings, and rounding has been applied. This value is recalculated each day and a short rolling average is applied. Therefore it may not be precisely accurate based on the other values presented.